Integrated energy conversion, transfer and storage system

ABSTRACT

An integrated hybrid energy recovery and storage system for recovering and storing energy from multiple energy sources is disclosed. The system includes an accumulator unit having a high pressure accumulator and a low pressure accumulator. At least one piston is mounted for reciprocation in the high pressure accumulator. The accumulator unit is configured to receive, store, and transfer energy from the hydraulic fluid to the energy storage media. The system further includes two or more rotational directional control valves, in which at least one rotational directional control valve is positioned on each side of the accumulator unit. Each rotational directional control valve includes multiple ports. The system also includes two or more variable displacement hydraulic rotational units. At least one variable displacement hydraulic rotational unit is positioned adjacent each of the rotational directional control valves.

TECHNICAL FIELD

The present disclosure relates to an energy conversion, transfer, andstorage system that is able to capture, store, and release energyaccording to the variable inputs outputs.

BACKGROUND Description of the Related Art

Current energy conversion systems rely on combustion processes,primarily internal combustion engines for mobile or stationaryapplications, or electrical motors powered by batteries or connected toan electrical network.

These systems operate under variable conditions based on energy need andpower generation requirements. Internal combustion engines for mobileapplications must operate under a wide range of power conditions, whichresults in increased consumption and emissions due to transientoperating conditions. Conventional brake energy recovery systems do notsolve the efficiency problem due to additional mass and limited usage.The operation of an engine at a constant speed under different outputconditions is a significant improvement, but requires an efficientintermediate energy storage device. Such a device could also improve theefficiency of the device that converts the chemical energy of the fuelinto thermal energy and then into mechanical energy.

Conventional stationary energy sources rely on the constant speed ofinternal combustion engines or gas/steam turbines at electricalgeneration plants. These systems rely on the fuel combustion associatedwith harmful and greenhouse gas emissions. Renewable energy sources likewind, wave, and solar are characterized by large fluctuations inavailability, increasing the need for flexibility, integratedcomplementarity among them, and also for intermediate storage.

Conventional vehicles and industrial processes generate large amounts ofwaste heat. The recovery of this energy needs reliable cost effectivetechnical solutions able to convert the waste heat into mechanical orelectrical energy.

The current systems, however, have disadvantages in their operation dueto efficiency, usability, flexibility, cost, applicability, weight,packaging, manufacturability, temperature range, recyclability anddurability.

Accordingly, it is an object of this disclosure to overcome theseshortcomings of conventional systems, and more specifically, to overcomeefficiency, packaging, weight, range of applicability, and manufacturinglimitations.

Relatively simple hydraulic systems have been used for thousands ofyears and throughout the history of civilization, such as for irrigationand the provision of mechanical power using, for example, water wheels.In modern times, hydraulic systems have become increasinglysophisticated, and are used in a wide variety of industries for a widevariety of purposes. In general, hydraulic systems use liquids, andparticularly pressurized liquids, to generate, control, and transmitmechanical power.

Various industrial, mechanical, and other systems, including many ofthose powered by renewable energy sources, rely on transient orintermittent energy or power generation. Thus, various systems for thetemporary storage of energy have been developed to collect energy whengeneration exceeds demand and to release energy when demand exceedsgeneration.

Further, regenerative braking systems have been developed for use invehicles such as automobiles, to recover and store a portion of thekinetic energy lost by the vehicle during deceleration. In such systems,energy that is otherwise typically dissipated by the vehicle's brakes isdirected by a power transmission system to an energy store duringdeceleration. Such stored energy is held until required again by thevehicle, at which point it is converted back into kinetic energy of thevehicle and is used to accelerate the vehicle. The magnitude of theportion of the kinetic energy lost during deceleration that is stored insuch systems depends on the type of storage and on drive trainefficiency.

Such systems have been widely used in electrified railways by invertingthe electric motors of trains and using them as generators while thetrain is braking. For internal combustion engine vehicles, however, ithas been more difficult to implement regenerative braking systemsbecause the energy conversion processes of internal combustion enginesare difficult to reverse.

In some implementations, batteries can be used as energy storagesystems, such as in regenerative braking systems, for use inautomobiles. Drive motors of electric vehicles can be made to operate asgenerators supplying a braking torque to the wheels. In regenerativebraking, the electric vehicle motor operates as a generator to charge abattery. The process is often less efficient at low speeds due to fixedmechanical losses, such that regeneration is often replaced orsupplemented by mechanical braking at low speeds. At present, however,batteries are relatively expensive and have various drawbacks impedingtheir widespread adoption.

In some implementations, hydraulic accumulators can be used as energystorage systems, such as in regenerative braking systems, for use inautomobiles. Hydraulic accumulators can operate by compressing a workinggas such as a nitrogen gas, or by raising a weight, or compressing orextending a mechanical spring or other elastomeric component. Hydraulicaccumulators are appealing due to their quiet operation, reliability,and durability. Compressed gas-based hydraulic accumulators areparticularly practical, in part because they are generally light,compact, and inexpensive. As with electric vehicles and batteries,however, these systems also tend to be inefficient at low speeds.

In some implementations, flywheels can be used as energy storagesystems, such as in regenerative braking systems, for use inautomobiles. Flywheels are appealing due to their relatively high energydensities and their capacity to provide high energy transfer rates.Flywheels have various drawbacks, however, including that practicalenergy densities are significantly lower than the theoretical values dueto losses arising from the weight of the associated bearings,motor/generator, shaft, and containment vessel. Various components offlywheels, their bearings, and their associated motors/generators alsooften use cooling systems to prevent overheating, adding complexity andcost. Further, safety is a concern because of a variety of potentialaccidental but catastrophic events.

In some implementations, elastomeric energy storage can be used as anenergy storage system, such as in regenerative braking systems, for usein automobiles. Elastomeric energy storage systems are promising becauseof their simplicity—in one implementation, the vehicle's driveline ismerely connected to an elastomer such that vehicle motion stresses theelastomer. Elastomeric energy storage systems have various drawbacks,however, including hysteresis or energy losses associated with cyclingof the elastomeric material. Hysteresis and cycling deteriorate and heatthe elastomer material, thereby reducing the achievable efficiency andreliability.

In some implementations, supercapacitors can be used as an energystorage system, such as in regenerative braking systems, for use inautomobiles. Supercapacitors, also known as ultracapacitors or Goldcap,are high-capacity capacitors with capacitance values much higher thanother capacitors, and bridge a gap between electrolytic capacitors andrechargeable batteries. Supercapacitors typically store many times moreenergy per unit volume or mass than electrolytic capacitors, can acceptand deliver energy more quickly than batteries, and tolerate morecharge-discharge cycles than rechargeable batteries. Supercapacitorsalso have various drawbacks, however, including smaller energy capacityper unit of weight relative to batteries, and complex electronic controland switching equipment.

In some implementations, recovery and conversion of heat into electricenergy, such as by the Rankine cycle, can be used as an energy storagesystem, such as in regenerative braking systems, for use in automobiles.In other implementations, thermo-electrical generator systems can beused as an energy storage system, such as in regenerative brakingsystems, for use in automobiles. In other implementations, recovery ofheat energy by the Rankine cycle and thermo-electrical generators areused in combination as an energy storage system, such as in regenerativebraking systems, for use in automobiles.

Since control of hydraulic systems is based on energy dissipation,hydraulic fluid tends to heat up and need cooling in order to maintain atemperature for proper performance of the hydraulic oil. Thus, heating ahydraulic fluid is generally considered to be detrimental. Hydraulicfluid cooling devices typically have a tubular structure, and employ oneor more coils to contain the hydraulic fluid proximate to the coolingfluid, according to a cross-flow principle for fluid, liquids, or air.State-of-the-art heat exchangers for hydraulic oil rely on one or moreof the three heat transfer mechanisms: convection, conduction, andradiation.

For cold running conditions, hydraulic heaters are used in which anelectrical resistor is immersed in the fluid reservoir. Constant runningconditions for fuel burners are used to heat buildings using liquid orgaseous fuels. In order to reduce nitrogen emissions, radiative burnersare currently under study in order to assure a low temperature flameand, consequently, low nitrogen emissions.

Current systems have, however, lacked in their operation due toefficiency, usability, flexibility, cost, applicability, weight,packaging, manufacturability, temperature range, recyclability, anddurability. Accordingly, it is the intent of this disclosure to overcomethese shortcomings of the prior art, and more specifically, to overcomeefficiency, packaging, weight, range of applicability andmanufacturability limitations.

There is a continuing need in the art for improved energy storage andregenerative braking systems, such as for use in automobiles, toovercome limitations that have been traditionally associated with suchexisting systems.

BRIEF SUMMARY

An Integrated Energy Conversion, Transfer, and Storage System isprovided to improve the efficiency of energy generation and consumptionfor systems that rely on variable energy generation or energyconsumption. The Integrated Energy Conversion, Transfer, and StorageSystem includes double-sided hydraulic units integrated withdouble-sided hydro-mechanical accumulator units and double-sideddirectional control valves to capture, store and release energyaccording to availability and power needs. The system integratesmechanical, hydraulic and thermal energy sources, releasing energy formultiple mechanical sources at different mechanical parameters andconnections than input and also releasing energy for electrical storageand consumption.

Considering that energy systems have to adapt to large power ranges inorder to cover applicability needs and that renewable energy ischaracterized by numerous fluctuations, the Integrated EnergyConversion, Transfer, and Storage System, in accordance with theexemplary embodiments of the present disclosure, is provided. In anintegrated manner, the Integrated Energy Conversion, Transfer, andStorage System includes double-sided hydraulic devices acting asvariable displacement hydraulic pumps or motors coupled with directionalcontrol valves and double-sided accumulator units. The core structure isextendable for multiple hydraulic inputs and hydraulic actuatedmechanical outputs coupled in series and parallel based on theparticular application.

Electrical output generation is also integrated. In addition tomechanical hydraulic energy generation, thermal energy is also convertedinto hydraulic energy and then into electrical or mechanical energy,according to the particular application. The embodiments are related toimproving the efficiency of energy systems like vehicles, renewableenergy sources allow them to run at higher efficiencies than currentapplications due to the intermediate storage capacity and flexible powerconversion capabilities given by fluid power. Relying on intermediateenergy storage allows applications of alternative conversion systemsthat might run at constant running conditions and consequently at higherefficiencies.

An integrated hybrid energy recovery and storage system for recoveringand storing energy from multiple energy sources may be summarized asincluding an accumulator unit that includes a high pressure accumulatorand a low pressure accumulator, the accumulator unit having a first sideand a second side; at least one piston mounted for reciprocation in thehigh pressure accumulator, the accumulator unit configured to receive,store, and transfer energy from the hydraulic fluid to energy storagemedia; two or more rotational directional control valves, wherein atleast one rotational directional control valve is positioned on eachside of the accumulator unit, each rotational directional control valveincludes multiple ports; the high pressure accumulator is connected to aport of the rotational directional control valve on the first side and aport of the rotational directional control valve on the second side, thelow pressure accumulator is connected to a port of the rotationaldirectional control valve on the first side and a port of the rotationaldirectional control valve on the second side; and two or more variabledisplacement hydraulic rotational units, wherein at least one variabledisplacement hydraulic rotational unit is positioned adjacent each ofthe rotational directional control valves, each variable displacementhydraulic rotational unit connected to a rotational directional controlvalve via a port of the rotational directional control valve and ahydraulic pipe.

The system may further include a first mechanical transmission with amechanical input coupling connected via a first mechanical shaft to oneof the variable displacement hydraulic rotational units of the two ormore variable displacement hydraulic rotational units.

The system may further include a second mechanical transmission with amechanical output coupling connected via a second mechanical shaft toanother of the variable displacement hydraulic rotational units of thetwo or more variable displacement hydraulic rotational units.

The system may further include a hydraulic connector that links the highpressure accumulator with a hydraulic circuit.

The system may further include a hydraulic connector that links the lowpressure accumulator with the hydraulic circuit.

The system may further include a pressure valve that enables hydraulicfluid to be released if peak loads occur to the low pressureaccumulator, by way of a connection pipe.

The system may further include a hydraulic pipe that is used as a bypassconnection to the high pressure accumulator. The energy storage mediamay be an elastic component.

The system may further include a controller that regulates transfer ofthe recovered energy in the accumulator. The controller may directpressurized hydraulic fluid to a variable displacement hydraulicrotational unit via a rotational directional control valve. The variabledisplacement hydraulic rotational unit may act as a motor driven bypressurized fluid. The system may be configured to recover, store, andrelease energy in a controlled manner based on availability and powerrequirements. The energy source may be radiative, electrical, vehicular,wind, wave, solar, or waste heat. The variable displacement hydraulicrotational unit may be able to act as a hydraulic pump, andalternatively the variable displacement hydraulic rotational unit may beable to act as motor.

The system may further include an energy recovery component thatrecovers energy from multiple energy sources.

The system may further include a thermal unit from which energy isrecovered by the system.

A hydraulic accumulator system may be summarized as including an outerhousing; a first open chamber within the outer housing; a second openchamber within the outer housing; an inner dividing wall that separatesthe first open chamber from the second open chamber; and a conduit thatextends through the inner dividing wall along a length of the hydraulicaccumulator system.

The hydraulic accumulator system may further include a hydraulic flowcontrol valve coupled to the first open chamber and to the second openchamber; and a hydraulic motor coupled to the hydraulic flow controlvalve.

The hydraulic accumulator system may further include a wheel coupled tothe hydraulic motor.

The hydraulic accumulator system may further include an axle extendingthrough the conduit, the wheel coupled to an end of the axle. The outerhousing may have a circular cross-sectional shape. The outer housing mayhave a elliptic cross-sectional shape. The inner dividing wall may beelastomeric and deformable, and the inner dividing wall may store energyby deforming when a first pressure within the first open chamber differsfrom a second pressure within the second open chamber. The first openchamber may include a high-pressure accumulator and the second openchamber may include a low-pressure accumulator.

The hydraulic accumulator system may further include an elastic elementpositioned within the first open chamber.

The hydraulic accumulator system may further include a first piston thatseals the elastic element within the first open chamber.

The hydraulic accumulator system may further include a second pistonthat seals the elastic element within the first open chamber. Theelastic element may be a mechanical helical spring. The elastic elementmay be a mechanical disc spring. The elastic element may be anelastomeric hose. The elastic element may be a compressed gas.

The hydraulic accumulator system may further include two elasticelements positioned within the first open chamber. The two elasticelements may have different elasticities.

The hydraulic accumulator system may further include three elasticelements positioned within the first open chamber.

The hydraulic accumulator system may further include a first portallowing hydraulic access to the first open chamber; and a second portallowing hydraulic access to the second open chamber.

The hydraulic accumulator system may further include a third portallowing hydraulic access to the first open chamber; and a fourth portallowing hydraulic access to the second open chamber.

A heat exchanger may be summarized as including a combustion chamberhaving an inlet port and an exhaust outlet port that define a combustiongas flow path between the inlet port and the exhaust outlet port; and afluid conduit oriented transverse to the combustion gas flow path, thefluid conduit directing the fluid through the combustion chamber, thefluid conduit including thermally conductive elements from which thefluid absorbs heat of combustion from within the combustion chamber.

The heat exchanger may further include a second inlet port, the firstand second inlet ports permitting two different fuel types to enter andmix within the combustion chamber.

A heat exchanger may be summarized as including a combustion chamberhaving an inlet port and an exhaust outlet port that define a combustiongas flow path between the inlet port and the exhaust outlet port; and afluid conduit coiled within the combustion chamber, the fluid conduitarranged in a circular path through the combustion chamber, the fluidconduit including thermally conductive elements from which a fluidwithin the fluid conduit absorbs heat of combustion from within thecombustion chamber.

A heat exchanger may be summarized as including a plurality of radiativeburners having a common inlet port, and a common exhaust outlet port,the radiative burners configured to transfer heat of combustion byradiation; and a plurality of fluid panels substantially aligned withone another and interdigitated with the radiative burners, the fluidpanels arranged to direct fluid in close proximity to the radiativeburners so as to absorb the heat of combustion.

A hybrid heat exchanger may be summarized as including a cylindricalcombustion chamber having an inlet port and an exhaust outlet port; acylindrical fluid chamber coaxial with, and internal to, the cylindricalcombustion chamber; and an electric heater having a resistive heatingelement that is coaxial with, and internal to, the cylindrical fluidchamber, the cylindrical fluid chamber thus arranged to absorb eitherheat of combustion from the combustion chamber, or heat radiated by theelectric resistive heater, or both radiated heat and heat of combustionat the same time.

A heat exchanger may be summarized as including an elongated heatsource; and a U-shaped fluid conduit that circulates fluid proximate tothe elongated heat source so as to absorb heat from the elongated heatsource, the U-shaped fluid conduit being made of a thermally conductivematerial. The elongated heat source may be a hot surface. The elongatedheat source may be a waste heat carrying fluid pipe.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the drawings, identical reference numbers identify similar elementsor acts. The sizes and relative positions of elements in the drawingsare not necessarily drawn to scale. For example, the shapes of variouselements and angles are not necessarily drawn to scale, and some ofthese elements may be arbitrarily enlarged and positioned to improvedrawing legibility. Further, the particular shapes of the elements asdrawn are not necessarily intended to convey any information regardingthe actual shape of the particular elements, and may have been selectedsolely for ease of recognition in the drawings.

FIG. 1 is a schematic view of an Integrated Energy Conversion, Transfer,and Storage System with double action functionality showing details of adouble-sided high pressure accumulator.

FIG. 2A is a schematic view of an Integrated Energy Conversion,Transfer, and Storage System with double action functionality showing astructure having an integrated hydrostatic transmission.

FIG. 2B is a schematic view of an Integrated Energy Conversion,Transfer, and Storage System with double action functionality showing asingle side structure.

FIG. 3 is a schematic view of an Integrated Energy Conversion, Transfer,and Storage System with double action functionality showing multipleoutput structures.

FIGS. 4A and 4B are schematic views of an Integrated Energy Conversion,Transfer, and Storage System with double action functionality showingstructures having an integrated direct mechanical transmission.

FIG. 5A is a schematic view of an Integrated Energy Conversion,Transfer, and Storage System with double action functionality showing astructure having an integrated power split transmission

FIG. 5B shows a sectional view A-A of the core Integrated EnergyConversion, Transfer, and Storage System.

FIGS. 6A and 6B are schematic views of an Integrated Energy Conversion,Transfer, and Storage System with double action functionality showing amultiple hydraulic unit structure.

FIG. 7 is a schematic view of an Integrated Energy Conversion, Transfer,and Storage System with double action functionality showing integrationof multiple additional hydraulic sources.

FIG. 8 is a schematic view of an Integrated Energy Conversion, Transfer,and Storage System with double action functionality showing integrationof a hydraulic optimization circuit and additional hydraulic sources.

FIG. 9 is a schematic view of an Integrated Energy Conversion, Transfer,and Storage System with double action functionality showing integrationof additional thermal borne hydraulic sources using a tubular structure.

FIG. 10 is a schematic view of an Integrated Energy Conversion,Transfer, and Storage System with double action functionality showingintegration of additional thermal borne hydraulic sources using aplanar/surface structure.

FIG. 11 is a schematic view of an Integrated Energy Conversion,Transfer, and Storage System with double action functionality showingintegration of additional thermal borne hydraulic sources using aplanar/surface structure having additional conduction support.

FIG. 12 is a schematic view of an Integrated Energy Conversion,Transfer, and Storage System with double action functionality showingintegration of an electrical linear generator based on a solid magneticelement or on magneto-hydrodynamics.

FIG. 13 is a schematic view of an Integrated Energy Conversion,Transfer, and Storage System integrating mechanical and thermal energysources for mechanical and electrical power supply.

FIG. 14 illustrates applicability of an Integrated Energy Conversion,Transfer, and Storage System for use with linear hydraulic actuators(hydraulic cylinders).

FIG. 15 illustrates an Integrated Energy Conversion, Transfer, andStorage System circuit with additional hydraulic flow source, optimizedusing a sonic resonating circuit—parallel connection—position a ofdirectional control valve.

FIG. 16 illustrates an Integrated Energy Conversion, Transfer, andStorage System circuit with additional hydraulic flow source, optimizedusing a sonic resonating circuit—series connection—position a ofdirectional control valve.

FIG. 17 illustrates an additional Integrated Energy Conversion,Transfer, and Storage System circuit with additional hydraulic flowsource, optimized using a sonic resonating circuit—position of adirectional control valve.

FIGS. 18A and 18B show pictorial views of components within anIntegrated Hydraulic Power and Control Unit of the Integrated EnergyConversion, Transfer, and Storage System.

FIGS. 19A, 19B, and 19C are radial cross-sectional views of anIntegrated Hydraulic Power and Control Unit.

FIG. 19D is a longitudinal cross-sectional view of an IntegratedHydraulic Power and Control Unit.

FIG. 20 is an exploded view of the accumulator side of an IntegratedHydraulic Power and Control Unit.

FIG. 21 is an exploded view of the actuation side of an IntegratedHydraulic Power and Control Unit.

FIGS. 22A, 22B and 22C are radial cross-sectional views of an IntegratedHydraulic Power and Control Unit.

FIG. 22D is a longitudinal cross-sectional view of an IntegratedHydraulic Power and Control Unit along an internal flow path ofmechanical and hydraulic energy.

FIG. 23 is an exploded view of an Integrated Hydraulic Power and ControlUnit showing an internal flow path of mechanical and hydraulic energy.

FIG. 24 illustrates an axial piston principle applied to an IntegratedEnergy Conversion, Transfer, and Storage System.

FIG. 25 is an exploded view of a multiple hydraulic systemsimplementation.

FIG. 26 is a longitudinal cross-sectional view of the multiple hydraulicsystems implementation shown in FIG. 25.

FIG. 27 is a block diagram showing the structure of a control system asdescribed herein.

FIG. 28 illustrates connectivity of directional control valve ports fordifferent running conditions.

FIG. 29 illustrates the structure of a fail-safe system that relievesexcess pressure that may accumulate in an Integrated Energy Conversion,Transfer, and Storage System.

FIG. 30A is a schematic diagram of a side elevation view of asingle-sided accumulator having a single elastic element, according toat least one illustrated embodiment.

FIG. 30B is a schematic diagram of a side elevation view of asingle-sided accumulator having two elastic elements, according to atleast one illustrated embodiment.

FIG. 30C is a schematic diagram of a cross-sectional end view of asingle-sided accumulator having two elastic elements, according to atleast one illustrated embodiment.

FIG. 30D is a schematic diagram of a side elevation view of asingle-sided accumulator having three elastic elements, according to atleast one illustrated embodiment.

FIG. 30E is a schematic diagram of a side elevation view of asingle-sided accumulator having three elastic elements and a hydrauliccylinder, according to at least one illustrated embodiment.

FIG. 31A is a schematic diagram of a side elevation view of adouble-sided accumulator having a single elastic element, according toat least one illustrated embodiment.

FIG. 31B is a schematic diagram of a side elevation view of adouble-sided accumulator having two elastic elements, according to atleast one illustrated embodiment.

FIG. 31C is a schematic diagram of a side elevation view of adouble-sided accumulator having three elastic elements coupled to oneanother in parallel, according to at least one illustrated embodiment.

FIG. 31D is a schematic diagram of a side elevation view of adouble-sided accumulator having three elastic elements coupled to oneanother in series, according to at least one illustrated embodiment.

FIG. 32A is a schematic diagram of a side elevation view of adouble-sided accumulator having parallel integrated high-pressure andlow-pressure accumulators, according to at least one illustratedembodiment.

FIG. 32B is a schematic diagram of a side elevation view of adouble-sided accumulator having parallel integrated high-pressure andlow-pressure accumulators, according to at least one illustratedembodiment.

FIG. 32C is a schematic diagram of a cross-sectional end view of adouble-sided accumulator having a high-pressure accumulator and alow-pressure accumulator, according to at least one illustratedembodiment.

FIG. 32D is a schematic diagram of a cross-sectional end view of adouble-sided accumulator having a high-pressure accumulator and alow-pressure accumulator, according to at least one illustratedembodiment.

FIG. 33A is a schematic diagram of a side elevation view of adouble-sided accumulator having concentric integrated high-pressure andlow-pressure accumulators, according to at least one illustratedembodiment.

FIG. 33B is a schematic diagram of a side elevation view of adouble-sided accumulator having continuously variable storage capacity,according to at least one illustrated embodiment.

FIG. 34 is a schematic diagram of an accumulator coupled to valves,actuators, and mechanical devices, according to at least one illustratedembodiment.

FIG. 35A illustrates a double-sided accumulator having a high-pressureaccumulator and a low-pressure accumulator, as well as a housing withtwo end caps, according to at least one illustrated embodiment.

FIG. 35B illustrates a double-sided accumulator having a high-pressureaccumulator and a low-pressure accumulator, as well as a housing withtwo end caps, according to at least one illustrated embodiment.

FIG. 36A illustrates a cross-sectional view of a double-sidedaccumulator having a high-pressure accumulator and a low-pressureaccumulator, according to at least one illustrated embodiment.

FIG. 36B illustrates cross-sectional and close-up views of adouble-sided accumulator having a high-pressure accumulator and alow-pressure accumulator, according to at least one illustratedembodiment.

FIG. 37A illustrates perspective and partially-exploded views ofcomponents of a double-sided accumulator having a high-pressureaccumulator and a low-pressure accumulator, according to at least oneillustrated embodiment.

FIG. 37B illustrates perspective and phantom views of components of adouble-sided accumulator having a high-pressure accumulator and alow-pressure accumulator, according to at least one illustratedembodiment.

FIG. 37C illustrates a close-up view of components illustrated in FIG.37A, according to at least one illustrated embodiment.

FIG. 37D illustrates some components illustrated in FIG. 37C isolatedfrom the rest of the system, according to at least one illustratedembodiment.

FIG. 37E illustrates perspective and exploded views of components of adouble-sided accumulator having a high-pressure accumulator and alow-pressure accumulator, according to at least one illustratedembodiment.

FIG. 38A is a schematic diagram of an accumulator having an integratedaxle coupled to valves, actuators, and mechanical devices, according toat least one illustrated embodiment.

FIG. 38B illustrates a double-sided accumulator having an integratedaxle, a high-pressure accumulator, and a low-pressure accumulator,according to at least one illustrated embodiment.

FIG. 38C illustrates a double-sided accumulator having an integratedaxle, a high-pressure accumulator, and a low-pressure accumulator,according to at least one illustrated embodiment.

FIG. 39A illustrates a double-sided accumulator having an integratedaxle, a high-pressure accumulator, and a low-pressure accumulator,according to at least one illustrated embodiment.

FIG. 39B illustrates a double-sided accumulator having an integratedaxle, a high-pressure accumulator, and a low-pressure accumulator,according to at least one illustrated embodiment.

FIG. 39C illustrates a double-sided accumulator having an integratedaxle, a high-pressure accumulator, and a low-pressure accumulator,according to at least one illustrated embodiment.

FIG. 40A illustrates an elliptical, double-sided accumulator having anintegrated axle, a high-pressure accumulator, and a low-pressureaccumulator, according to at least one illustrated embodiment.

FIG. 40B illustrates an elliptical, double-sided accumulator having anintegrated axle, a high-pressure accumulator, and a low-pressureaccumulator, according to at least one illustrated embodiment.

FIG. 41A illustrates an integrated set of multiple accumulators,according to at least one illustrated embodiment.

FIG. 41B illustrates an integrated set of multiple accumulators,according to at least one illustrated embodiment.

FIG. 41C illustrates an exploded view of an accumulator having anintegrated axle, a high-pressure accumulator, and a low-pressureaccumulator, according to at least one illustrated embodiment.

FIG. 41D illustrates a top plan view of an accumulator having anintegrated axle, a high-pressure accumulator, and a low-pressureaccumulator, according to at least one illustrated embodiment.

FIG. 41E illustrates a side view of an accumulator having an integratedaxle, a high-pressure accumulator, and a low-pressure accumulator,according to at least one illustrated embodiment.

FIG. 41F illustrates a cross-sectional view of an accumulator having anintegrated axle, a high-pressure accumulator, and a low-pressureaccumulator, according to at least one illustrated embodiment.

FIG. 41G illustrates a cross-sectional view of an accumulator having anintegrated axle, a high-pressure accumulator, and a low-pressureaccumulator, according to at least one illustrated embodiment.

FIG. 42A illustrates a hydraulic system including a hydraulicaccumulator, according to at least one illustrated embodiment.

FIG. 42B illustrates a hydraulic system including a hydraulicaccumulator, according to at least one illustrated embodiment.

FIG. 42C illustrates a cross-sectional view of a hydraulic accumulator,according to at least one illustrated embodiment.

FIG. 42D illustrates a cross-sectional view of an alternativeimplementation of a hydraulic accumulator, according to at least oneillustrated embodiment.

FIG. 43 is a block diagram illustrating a general structure of a fluidthermal unit, according to an embodiment as described herein.

FIG. 44 is a transparent pictorial perspective view of a cross-flow heatexchanger subsystem having a rectangular shape, according to anembodiment as described herein.

FIG. 45 is a schematic diagram of an ultrasound generator of combustionair, according to an embodiment as described herein.

FIG. 46 is a cutaway view of the internal components of an integratedcircular convection thermal unit, according to an embodiment asdescribed herein.

FIGS. 47A, 47B, 47C, and 47D illustrate results of a CFD simulation offluid flow within the thermal unit shown in FIG. 46.

FIG. 48 is a block diagram showing a liquid thermal unit that canreceive fuel from multiple sources, according to an embodiment asdescribed herein.

FIG. 49 is a schematic diagram of a liquid thermal unit equipped withemission reduction components, according to an embodiment as describedherein.

FIG. 50 is a table showing properties of, and relationships between,various emission reduction principles.

FIG. 51A is an end view of a fluid thermal unit implemented as aradiative burner, according to an embodiment as described herein.

FIG. 51B is an exploded side view of the radiative burner shown in FIG.51A.

FIG. 52A is a schematic side view of a hybrid electrical andcombustion-based fluid thermal unit, according to an embodiment asdescribed herein.

FIG. 52B is a pictorial view of a heater body into which fluid entersvia an inlet pipe and leaves via an outlet pipe, according to anembodiment as described herein.

FIG. 53 is a cutaway view of components of the integrated circularconvection thermal unit shown in FIG. 4, enhanced with an add-onelectric heater.

FIG. 54 is a schematic view of a pipe-based fluid heat transfer system,according to an embodiment as described herein.

FIG. 55 is a pictorial view of the pipe-based fluid heat transfer systemshown in FIG. 54, enhanced by an insulating layer.

FIG. 56 is a perspective view of a pipe-based heat transfer system,according to an embodiment as described herein.

FIG. 57 is a schematic view of a radiative heat transfer system,according to an embodiment as described herein.

FIG. 58 is a schematic view of the radiative heat transfer system shownin FIG. 57, enhanced by a plurality of highly-conductive pins.

FIG. 59A is a schematic view of a thermal unit using wax thermalexpansion and phase change.

FIG. 59B is a cross-sectional view of a thermal unit using wax thermalexpansion and phase change, along line A-A from FIG. 59A.

DETAILED DESCRIPTION

In the following description, certain specific details are set forth inorder to provide a thorough understanding of various disclosedembodiments. However, one skilled in the relevant art will recognizethat embodiments may be practiced without one or more of these specificdetails, or with other methods, components, materials, etc. In otherinstances, well-known structures associated with the technology have notbeen shown or described in detail to avoid unnecessarily obscuringdescriptions of the embodiments.

Unless the context requires otherwise, throughout the specification andclaims that follow, the word “comprising” is synonymous with“including,” and is inclusive or open-ended (i.e., does not excludeadditional, un-recited elements or method acts).

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure or characteristicdescribed in connection with the embodiment is included in at least oneembodiment. Thus, the appearances of the phrases “in one embodiment” or“in an embodiment” in various places throughout this specification arenot necessarily all referring to the same embodiment. Furthermore, theparticular features, structures, or characteristics may be combined inany suitable manner in one or more embodiments.

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include plural referents unless the contextclearly dictates otherwise. It should also be noted that the term “or”is generally employed in its broadest sense, that is, as meaning“and/or” unless the context clearly dictates otherwise.

The headings and Abstract of the Disclosure provided herein are forconvenience only and do not limit the scope or meaning of theembodiments.

As shown in FIG. 1, in some implementations of the Integrated EnergyConversion, Transfer, and Storage System employ integratedmechanical-hydraulic energy conversion. This type of integratedmechanical-hydraulic energy conversion provides the technologicalimprovement of integrating hydraulic units, such as directional controlvalves and accumulator units. Additionally, the Integrated EnergyConversion, Transfer, and Storage System incorporates a dual-actionconfiguration that reduces flow speed and hydraulic power loss.Furthermore, the Integrated Energy Conversion, Transfer, and StorageSystem integrates different energy sources and energy outputs.

The implementation of the Integrated Energy Conversion, Transfer, andStorage System shown in FIG. 1 is positioned between a mechanicaltransmission 102 with a mechanical input coupling 104 on one end and amechanical transmission 148 with a mechanical output coupling 146 on theother end. In this implementation, the Integrated Energy Conversion,Transfer, and Storage System achieves the technological functions ofactive control of the mechanical output parameters, intermediate energystorage, and direct connection of a mechanical input coupling 104 and amechanical output coupling 146.

Some implementations of the Integrated Energy Conversion, Transfer, andStorage System utilize the coupling of a variable displacement hydraulicpower unit (HU1) connected to the mechanical input coupling 104, with adirectional control valve 110 on one side of an accumulator unit (AU).On the other side of the accumulator unit is coupled a directionalcontrol valve 140 connected to a variable displacement hydraulic powerunit (HU2), which is mechanically connected to the mechanical outputcoupling 146. A mechanical shaft 106 provides a direct connection to themechanical input coupling 104 on one end and a mechanical shaft 144provides a direct connection of the mechanical output coupling 146 onthe other end.

In the Integrated Energy Conversion, Transfer, and Storage System, themechanical rotational energy provided by the mechanical couplings 104and 146 is converted into hydraulic energy by the variable displacementhydraulic power units HU1 and HU2, which direct the hydraulic energy tothe accumulator unit AU. The hydraulic energy may then fill theaccumulator unit AU. As a result, all or part of the transmittedmechanical energy is stored by the displacement imposed by the variabledisplacement hydraulic power units HU1 and HU2. When the stored energywithin the accumulator unit AU is released by the displacement of thevariable displacement hydraulic power units, the hydraulic energy isconverted into mechanical energy and added to the mechanical powertransferred between the mechanical input coupling 104 and the mechanicaloutput coupling 146. The directional control valves 110 and 140 switchbetween input and output of the connections of the hydraulic power unitsHU1 and HU2 to the accumulator unit AU.

In at least one implementation of the Integrated Energy Conversion,Transfer, and Storage System, the components of the variabledisplacement hydraulic power units HU1 and HU2, directional controlvalves 110 and 140, and accumulator unit AU are integrated, which allowsa larger flow path and reduced flow velocities. Accordingly, theIntegrated Energy Conversion, Transfer, and Storage System increasessystem efficiency by reducing flow losses. An additional benefit of thiscomponent integration is significant mass reduction. By having twohydraulic units connected to the accumulator unit, the flow is decreasedby a factor of two. Thus, the hydraulic power losses are reduced by afactor of eight (i.e., the cube power of the velocity reduction).

In some implementations, the Integrated Energy Conversion, Transfer, andStorage System may be configured to extend to multiple energy inputsources, as well as multiple mechanical and/or electrical sources. Thestructure of the system may be extended using a hydraulic input systemthat includes hydraulic pipes connected between the directional controlvalves and the hydraulic input system. Additionally, the structure ofthe Integrated Energy Conversion, Transfer, and Storage System may beextended by using a sonic electrical generator that includes hydraulicpipes connected between the directional control valves 110 and 140 andthe sonic electrical generator. Further, the structure of the IntegratedEnergy Conversion, Transfer, and Storage System may be extended by usingmultiple mechanical outputs.

In at least one implementation, the Integrated Energy Conversion,Transfer, and Storage System includes a single hydraulic unit, whichintegrates the variable displacement hydraulic rotational unit 108 andthe rotational directional control valve 110 with the accumulator unit,which integrating the high pressure accumulator 116 and the low pressureaccumulator 124. In other implementations, the Integrated EnergyConversion, Transfer, and Storage System includes dual hydraulic unitspositional on opposite sides of the accumulator unit.

In some implementations of the Integrated Energy Conversion, Transfer,and Storage System, the hydraulic unit HU1 includes the variabledisplacement hydraulic rotational unit 108 and the rotationaldirectional control valve 110. The variable displacement hydraulicrotational unit 108 acts alternately as hydraulic pump or motor bytransferring mechanical torque that is coupled to the mechanicaltransmission 102 via the shaft 106 and coupling 104. The hydrauliccircuit includes rotational directional control valve 110, which createsflow connections of the inlet and outlet ports A and B, of the variabledisplacement hydraulic rotational unit 108 with the high pressureaccumulator 116 using port C and the low pressure accumulator 124 usingport D.

Located within the high pressure accumulator 116 is piston 118 thattransfers energy from the hydraulic fluid to the energy storage media120, which is an elastic component. The hydraulic connector 114 linksthe high pressure accumulator 116 with the hydraulic circuit. Thepressure valve 112 enables hydraulic fluid to be release if peak loadsoccur to the low pressure accumulator 124, by way of the connection pipe122. The low pressure accumulator 124 is connected to the hydrauliccircuit by hydraulic connector 126.

In the implementation shown in FIG. 1, the Integrated Energy Conversion,Transfer, and Storage System has a dual-action configuration. Thisdual-action configuration is an extension of a single action brakeenergy recovery system. The dual-action configuration of the IntegratedEnergy Conversion, Transfer, and Storage System creates a mechanicaltorque transfer path between two rotational mechanical transmissions 102and 148. The dual-action configuration has intermediate energy storagecapabilities from the rotational mechanical transmissions 108 and 148,and can change the torque transferred between the rotational mechanicaltransmissions.

The dual action implementation of the Integrated Energy Conversion,Transfer, and Storage System uses the hydraulic unit HU2 coupled to theaccumulator unit AU in addition to hydraulic unit HU1. The hydraulicunit HU2 has the same construction as hydraulic unit HU1. The hydraulicunit HU2 includes rotational directional control valve 140 and variabledisplacement hydraulic rotational unit 142, which connect to thehydraulic connector 134 of the high pressure accumulator 116, andpressure valve 136 which is connected to the low pressure accumulator124 using hydraulic pipe 138. The hydraulic unit HU1 is also connectedto the low pressure accumulator 124 using hydraulic coupling 150.

In some implementations, the Integrated Energy Conversion, Transfer, andStorage System also includes a rotational directional control valve 140includes ports A′ and B′ connected to variable displacement hydraulicrotational unit 142, port C′ to high pressure accumulator 116, and portD′ to the low pressure accumulator 124. The variable displacementhydraulic rotational unit 142 is connected to mechanical transmission148 via the mechanical shaft 144 and mechanical coupling 146.

In a dual action implementation of the Integrated Energy Conversion,Transfer, and Storage System, the accumulator unit includes a highpressure accumulator 116 and the low pressure accumulator 124. Ahydraulic piston 118 is positioned within high pressure accumulator 116and converts the hydraulic energy of the fluid flow transferred byvariable displacement hydraulic rotational unit 108 and controlled byrotational directional control valve 110 to storage media 120. Ahydraulic piston 132 is also positioned within the high pressureaccumulator 116, and converts the hydraulic energy of the fluid flowtransferred by variable displacement hydraulic rotational unit 142 andis controlled by rotational directional control valve 140 to the storagemedia 130. Storage media 130 is sustained against the walls and thestorage media 120 by the supporting wall 128.

Referring now to FIG. 2A, an implementation of the Integrated EnergyConversion, Transfer, and Storage System is shown with an integratedhydrostatic transmission. The integrated hydrostatic transmission addsthe additional capability to the system of integrating a continuousvariable transmission between mechanical transmission 102 and mechanicaltransmission 148. Specifically, a hydraulic pipe 152 is used as a bypassconnection to the high pressure accumulator 116. In this implementation,the rotational directional control valve 110 includes an additional portE and rotational directional control valve 140 includes an additionalport E′. Hydraulic pipe 152 is connected between ports E and E′.

In a single sided implementation of the Integrated Energy Conversion,Transfer, and Storage System, as shown to FIG. 2B, the double actionfunctionality of the accumulator unit is incorporated into a singlemechanical transmission. The rotational directional control valve 140includes port C′ that is connected to high pressure accumulator 116, anda port E′ that is connected to low pressure accumulator 124. This singlesided implementation of the Integrated Energy Conversion, Transfer, andStorage System, does not include the variable displacement hydraulicrotational unit 142, the mechanical shaft 144, the mechanical coupling146, or the mechanical transmission 148.

Referring now to FIG. 3, other implementations of the Integrated EnergyConversion, Transfer, and Storage System are shown with multiple poweroutputs. In the first implementation, all output actuators arecontrolled by a single directional control valve. This implementationdemonstrates system structures that are hydraulically connected inparallel. For this implementation the hydraulic circuit splits betweenrotational directional control valve 140 and variable displacementhydraulic rotational unit 142, which establishes a hydraulic circuit toconnect additional variable displacement hydraulic rotational unit 154.The hydraulic circuit includes hydraulic pipes 162 and 164. Variabledisplacement hydraulic rotational unit 154 transfers torque tomechanical transmission 160, using the mechanical shaft 156 and themechanical coupling 158.

In the second implementation of the Integrated Energy Conversion,Transfer, and Storage System, separate control is provided to eachoutput actuator. This implementation includes an additional rotationaldirectional control valve 174, which has similar connecting ports A″,B″, C″, D″, E″, F″ as rotational directional control valve 140. Theadditional rotational directional control valve 174 is connected usinghydraulic pipes 176, 178, 180. The variable displacement hydraulicrotational unit 166 transfers torque to the mechanical transmission 172using the mechanical shaft 168 and the mechanical coupling 170.

Referring now to FIG. 4A, in some implementations, the Integrated EnergyConversion, Transfer, and Storage System includes an integratedmechanical transmission with a direct mechanical torque transfer path.In this implementation, the direct mechanical torque transfer path is atorque transfer shaft 182 between two rotational mechanicaltransmissions 102 and 148 that are directly connected to mechanicalcouplings 104 and 146. The torque transfer shaft 182 is connected to therotational mechanical transmissions 102 and 148 without intermediatehydraulic energy conversion. The mechanical design of the accumulatorunit and hydraulic units relies on creating a hollow path for torquetransfer shaft 148.

Referring now to FIG. 4B, in some implementations, the Integrated EnergyConversion, Transfer, and Storage System includes an integrated powersplit transmission. In this implementation, the integrated power splittransmission includes the additional components of gear set 184 rigidlyconnected to mechanical shaft 106 and gear set 186 rigidly connected tomechanical shaft 144. The outputs of gear sets 184 and 186 are connectedby mechanical shaft 188. In this implementation, the torque transfer maybe continuously adjusted by adjusting the displacement of the variabledisplacement hydraulic rotational units 108 and 142.

Referring now to FIGS. 5A-5B, some implementations of the double actionIntegrated Energy Conversion, Transfer, and Storage System have amultiple hydraulic unit configuration. With regard to the implementationdepicted in FIG. 5A, the core assembly of Integrated Energy Conversion,Transfer, and Storage System includes two hydraulic power and controlunits and the included accumulator units. Additional core assemblies ofIntegrated Energy Conversion, Transfer, and Storage System may be linkedto the propulsion shaft by gear sets in a modular manner to createflexible, larger energy storage and conversion capacities. Specifically,FIG. 5A illustrates the connection of two core assemblies of IntegratedEnergy Conversion, Transfer, and Storage System to propulsion shaftsusing gear sets 190 and 192. FIG. 5B shows a sectional view A-A of thecore Integrated Energy Conversion, Transfer, and Storage System. Thisview illustrates how the Integrated Energy Conversion, Transfer, andStorage System may be positioned to meet packaging constraints.

Referring now to FIGS. 6A-6B, an implementation of the Integrated EnergyConversion, Transfer, and Storage System is shown with additional coreassemblies. The additional core assemblies integrate the propulsionshafts using gear sets 194, 196, 198 and 200.

FIG. 7 illustrates an implementation of the Integrated EnergyConversion, Transfer, and Storage System with double actionfunctionality that integrates an additional hydraulic source. In someimplementations, additional hydraulic flow sources may be incorporatedto integrate the additional hydraulic source with the Integrated EnergyConversion, Transfer, and Storage System. In such implementations,hydraulic pipes 202 and 204 provide a connection from the additionalhydraulic flow sources to the directional valves of Integrated EnergyConversion, Transfer, and Storage System using additional ports F andF′.

In implementations in which additional hydraulic sources are available,as well as additional Integrated Energy Conversion, Transfer, andStorage Systems to be connected, the additional hydraulic sources areconnected in parallel. An example of a multiple additional hydraulicflow source application is a combined wind wave application as describedin related application Serial No. entitled “Integrated Renewable Energyand Waste Heat Harvesting System,” App. Ser. No. 62/606,521, filed Sep.26, 2017, which is incorporated by reference herein in its entirety.

Referring now to FIG. 8, to improve hydraulic performance, a generichydraulic optimization circuit is included between the basic additionalhydraulic flow source and the Integrated Energy Conversion, Transfer,and Storage System. An example of a hydraulic optimization circuit is asonic circuit as described in related application Ser. No. 15/731,360,filed Jun. 1, 2017, entitled “Thermo-Hydraulic Pressure Wave BasedPropulsion System,” which is incorporated by reference in its entirety.

Referring now to FIG. 9, in implementation of an Integrated EnergyConversion, Transfer, and Storage System is shown with double actionfunctionality that integrates additional thermal hydraulic sources. Thisimplementation adds heat to a flowing media. The flowing media is heatedto accumulate energy from an external heat source and release the energyto the hydraulic core system. To implement this cycle, pipe 204 isconnected to the port F′ of the core Integrated Energy Conversion,Transfer, and Storage System. The hydraulic power and control unit Aacts as hydraulic pump for the thermal unit. The thermal unit includes ahydraulic liquid jacket 208 that has a circular shape and surroundingpipe 210 that is the flow path for the fluid (e.g., gas or liquid) whereheat transfer develops, which may be wither heating or cooling.

In the implementation of the Integrated Energy Conversion, Transfer, andStorage System shown in FIG. 9, the outer material of the cooling jacket208 includes an insulating material. Notably, the pipe assemblies 208and 210 act as a counter-flow convective-conductive heat exchanger. Tocreate the flow circuit, the one-way valve 206 provides the flow pathfrom hydraulic power and control unit A, which acts as a hydraulic pump,to the directional control valve of the hydraulic power and control unitB via port F. At the hydraulic power and control unit B, the thermalenergized liquid is directed to the accumulator unit or the variabledisplacement power unit which acts as a hydraulic motor. An example of aconvective-conductive hydraulic heat exchanger is described in Ser. No.15/731,360, filed Jun. 1, 2017, which is incorporated by referenceabove.

Referring now to FIG. 10, in some implementations of the IntegratedEnergy Conversion, Transfer, and Storage System, a radiative heat sourceis integrated into the system. In one such implementation, the planeradiative surface 214 is placed in front of the rectangular flow space212 as shown in sectional view A-A, for a maximum radiative view factor.The flow space contains the fluid that is driven by the hydraulic powerand control unit A towards the accumulator unit and/or the hydraulicpower and control unit B.

As shown in the implementations of the Integrated Energy Conversion,Transfer, and Storage System of FIG. 11, conduction heat transfer fromthe radiative surface may be enhanced by using conduction pins 216,which are placed in contact with the hot surface 214, and integratedwithin the flow path 212. The conduction pins 216 increase the contactsurface of the work liquid with the heat source, thereby generating acombined radiative-conduction heat source. An example of a radiativeconductive hydraulic heat exchanger is described in Ser. No. 15/731/360,filed Jun. 1, 2017, as incorporated by reference above.

Referring now to FIG. 12, some implementations of the Integrated EnergyConversion, Transfer, and Storage System with double actionfunctionality additionally include an integrated electrical generator.In such an implementation, the Integrated Energy Conversion, Transfer,and Storage System is expanded with an integrated electrical system tostore energy by electrical matter, as well as to feed an electricalconsumer or network. Some such implementations of the Integrated EnergyConversion, Transfer, and Storage System incorporate an alternatinglinear generator. In the implementation shown in FIG. 12, thealternating linear generator includes a magnetic core 252 that ismounted rigidly to hydraulic pistons 250 and 262. The magnetic core 252is surrounded by an electromagnetic coil 264. Accordingly, electricalcurrent is induced due to linear alternating displacement of magneticcore 276. The induced current is directed to an electrical storage media(battery) 270 using electrical wires 266 and 268. Additionally, theelectrical storage media 270 is connected to an electrical actuator oran electrical network 274 using electrical wires 272.

In some implementations, pressure from the hydraulic circuit actuateshydraulic pistons 242 and 256, which generate the alternating lineardisplacement of the magnetic element 252 between the hydraulic cylinders240 and 254. The neutral position of magnetic core 252 is maintained bythe spring 244 acting between hydraulic piston 242 and rigid fixed wall246, and the spring 258 acting between hydraulic piston 256 and rigidfixed wall 260. The hydraulic cylinders are connected to IntegratedEnergy Conversion, Transfer, and Storage System using hydraulic valves218 and 220 connected to the high pressure accumulator of theaccumulator unit, and hydraulic valves 222 and 224 are connected to thelow pressure accumulator of the accumulator unit. High pressure pipes226 and 228 are linked by hydraulic pipe 230, and are connected to portP of the rotational valve 232. During rotation, the rotational valve 232provides two different connection combinations. The first connectioncombination is P-A and B-T at the same time. The second connectioncombination is P-B and A-T at the same time.

Referring still to FIG. 12, in some implementations of the IntegratedEnergy Conversion, Transfer, and Storage System, Port A is connected viahydraulic pipe 234 to hydraulic cylinder 240, and Port B is connectedvia hydraulic pipe 236 to hydraulic cylinder 254. Additionally, Port Tis connected central pipe 238, which provides a connection at the lowpressure accumulator of the accumulator unit by the hydraulic connectorsa-a′ and b-b′.

In at least one implementation of the Integrated Energy Conversion,Transfer, and Storage System, the magnetic core 252 is actuated usinghydraulic fluid from the accumulator unit. The hydraulic fluid from theaccumulator unit is directed to port P of the rotational control valve232. Due to the rotation of the rotational control valve 232, the liquidat port P is directed alternately to ports A and B. Consequently, thepistons 242 and 256 generate the alternating displacement of themagnetic core 252, which is fixed to the pistons 242 and 256.Concurrently, the rotational control valve 232 provides alternatingconnection of Port B to T and A to T, which releases liquid at the endof the stroke from hydraulic cylinders 240 and 254, to the low pressureaccumulator of the accumulator unit. In some implementations, themagnetic core 252 is an electromagnetic-suitable liquid which isactuated within housing 276 by hydraulic pistons 250 and 262 to induceelectrical current into the coil 264.

Referring now to FIG. 13, the general Integrated Energy Conversion,Transfer, and Storage System structure further integrates a thermalenergy source 275A. The thermal energy source 275A has a mechanicalinterface 275B and an electrical interface 275C. The thermal energysource 275A connects via the mechanical interface 275B and theelectrical interface 275C to the directional control valves of theHydraulic Power and Control Units via ports 273A and 273B.

Referring now to FIG. 14, in some implementations of the IntegratedEnergy Conversion, Transfer, and Storage System, the hydraulic powerunits incorporate alternating linear displacement. In such animplementation, the Integrated Energy Conversion, Transfer, and StorageSystem incorporates translational displacement loads 277A and 277B,which are connected to piston rods 281A and 281B. The piston rods 281Aand 281B are housed in double acting hydraulic cylinders 279A and 279B.The double acting hydraulic cylinders 279A and 279B further househydraulic pistons. The translational displacement loads 277A and 277Bprovide alternating linear displacement to the Integrated EnergyConversion, Transfer, and Storage System via the piston rods 281A and281B, the double acting hydraulic cylinders 279A and 279B, and thehydraulic pistons.

Referring now to FIG. 15, an implementation of an efficiencyoptimization circuit is shown, in accordance with the configuration inFIG. 8. The efficiency optimization is integrated between a hydraulicenergy generation source and a hydraulic energy load. The hydraulicenergy generation source and the hydraulic energy load each include ahigh pressure side and a low pressure side. In this implementation, thesides of the hydraulic circuit provide alternating pressure to generateoscillations that create hydraulic inertia and capacity. In someimplementations, the oscillations and the hydraulic inertia generateresonance conditions. To create these conditions, two 2/4 (twoposition/4 port) directional control valves 278 and 280 are used, asshown in FIG. 15.

In such an implementation, when directional control valve 278 is in the“a” position, the liquid from the high pressure side of the hydraulicflow source flows through pipe 282 towards directional control valve280. The directional control valve 280 directs the fluid to the highpressure side of the hydraulic energy load. The low pressure side of thehydraulic flow source and hydraulic energy load are connected by pipe284 that is positioned between directional control valves 278 and 280.Concurrently, due to the pressure in the pipe 282, the piston 290 incylinder 286 is pushed against the spring 292 which sits on theseparation wall 288. Due to the low pressure in pipe 284, the spring 294pushes piston 296 to its outside extreme position. By switching thepositions of directional control valves 278 and 280 to the “b” position,the high pressure circuit generated by the new positions of directionalcontrol valves 278 and 280 is directed through pipe 284.

Referring still to FIG. 15, due to the pressure change that occurs byswitching the position of the directional control valves 278 and 280,the piston 296 within hydraulic cylinder 286 is pushed against spring294 that sits on separation wall 288. Concurrently, due to low pressurein pipe 282, piston 290 is pushed to its extreme outside position byspring 292. By periodically switching between positions “a” and ‘b” ofdirectional control valves 278 and 280, the mass spring systems, whichinclude piston 290 and related spring 292 on one side and piston 296 andspring 294 on the other side, will oscillate. The mass of the pistons,spring rate, and oscillating frequency are chosen to meet resonanceconditions to increase the efficiency and reduce losses of resonance. Insome implementations, the overall connectivity of the high pressure andlow pressure sides of the hydraulic flow source and hydraulic energyload is not affected. Additionally, hydraulic accumulators 298 and 300are employed to compensate for oscillations in the non-resonating partof the circuit.

Referring now to FIG. 16, in implementations where fluid separation isdesired to be obtained, connection pipes 282 and 284 are split, andpistons 290 and 296 also function as a mechanical separator. The pipe282 directs the fluid in front of piston 290 which pushes the liquidadjacent the piston through pipe 282′ towards directional control valve280. In the same manner, pipe 284 directs the fluid in front of piston296 which separates the space relative to the fluid in pipe 284. Theflow space adjacent piston 296 is connected to pipe 284′ which isconnected to directional control valve 280.

Referring now to FIG. 17, in some implementations the positioning of thecomponents is configured for series connectivity of the resonatingassembly. The resonating assembly includes hydraulic cylinder 286 withspring 292 placed between and acting against pistons 290 and 296 whichare in contact with the liquid in pipes 282 and 282′ and rely on ⅔directional control valves. In this implementation, the separation wall288 is removed from the parallel connection and only one spring is used.In the “a” position of the directional control valves 278 and 290, thehydraulic circuit is under pressure. When the spring 96 is compressed inthe “b” position, the hydraulic circuit is released and the springexpands. The correlation of valve opening/closing frequency, the mass ofthe pistons, and the spring rates for resonance define the assembly. Theassembly includes hydraulic cylinder 286, pistons 290 and 296, andspring 292, as a hydraulic resonator.

In various implementations of the Integrated Energy Conversion,Transfer, and Storage System, as described with respect to FIGS. 1-17,any type of hydraulic pump/motor assembly may be integrated with theIntegrated Energy Conversion, Transfer, and Storage System. Thedescription provided below relates to the vane and axial pistonimplementations, as examples of such integration. Typically, vane typeimplementations involve lower cost and noise, while axial piston typeimplementations involves higher working pressure and lower drag torque.Both the vane and axial piston implementations involve the axialdirection integrating in a more compact manner with the accumulatorunit. This type of axial direction integration is suitable for mobileapplications. Another implementation, such a radial piston configurationfor the hydraulic power unit, may also be employed in situations that donot require strict packaging constraints. Notably, a rotationaldirectional control valve is suitable for all implementations to achieveproper integration.

In some implementations, during vehicle operation when the IntegratedEnergy Conversion, Transfer, and Storage System is not employed, thedisplacement of the variable displacement hydraulic rotational unit isset to zero, so no mechanical-hydraulic torque is transferred. In suchan implementation, a minimum drag torque is provided.

In another implementation, during an intermediate energy storage runningmode, the displacement of the variable displacement hydraulic rotationalunit is set to its maximum position and the port connections of therotational directional control valve rotates so that connections A to Cand B to D are established. The variable displacement hydraulicrotational unit is rotated by the mechanical coupling and shaft poweredby the attached mechanical system through the mechanical transmission.The hydraulic liquid is absorbed from the low pressure accumulator andpushed within the high pressure accumulator, which actuates the pistonin a single-sided implementation. In a double-sided implementation, twopistons are actuated. The pistons are connected to the storage elementstores energy using deformation and force transferred from the pistons.

When the accumulator exceeds its storage capacity, which is a conditionmonitored as a failsafe function, the high pressure accumulator closesas a result of a new position that is obtained by the rotationaldirectional control valve. The failsafe function is described above withreference to FIG. 2. The new position of the rotational directionalcontrol valve connects the output of the variable displacement hydraulicrotational unit to the low pressure accumulator by a controlled localresistance. This controlled local resistance provides a hydraulic brake(retarder mode) if further braking is needed (e.g., a downhill run).Alternatively, the displacement of the variable displacement hydraulicrotational unit is set to zero if accumulated energy has to be stored.

In some implementations, the stored energy is used by rotating therotational directional control valve to a new position. The rotationaldirectional control valve connects the high pressure accumulator to thevariable displacement hydraulic rotational unit input and the output tothe low pressure accumulator. If the same rotational direction ismaintained for the variable displacement hydraulic rotational unit asduring energy storing, then the connections to the high and low pressureaccumulator must be reversed. For example, during the stopping andstarting that takes place at a traffic light, the connections to thehigh and low pressure accumulator must be reversed if the IntegratedEnergy Conversion, Transfer, and Storage System is used as a brakeenergy recovery system for vehicles. The same connectivity of the portsof the rotational directional control valve that occurs during energystorage acts to generate a reversed rotational direction from theconfiguration is maintained during braking. If the Integrated EnergyConversion, Transfer, and Storage System is implemented as a brakeenergy recovery system for vehicles, this configuration is useful whenstarting the vehicle after it has been parked.

Since the Integrated Energy Conversion, Transfer, and Storage Systemwith double action functionality employs on two variable displacementhydraulic rotational units, a hydrostatic transmission is established bydirect connection of the two variable displacement hydraulic rotationalunits. This configuration provides an additional function of thehydrostatic transmission mode that is useful to provide a continuousvariable transmission ratio in a broad range, but with less efficiencythan a mechanical transmission.

The broad range and rapid response make this configuration useful forshort period of time when peak torque is needed, such as accelerating topass another vehicle on a freeway, or driving in high resistanceconditions, e.g., driving through sand, driving up a steep slope, or thelike. This configuration is also useful for continuous adjustment of thedisplacements of the variable displacement hydraulic rotational units,so that the internal combustion engine can easily switch betweenoperation on more fuel efficient curves of the engine map, operation onconditions that occur during city driving, or operation on off roadconditions. When operating in this configuration, short termintermediate storage and retrieve of energy is achieved.

Referring now to FIGS. 18A and 18B, the relationship of the corecomponents of the Integrated Energy Conversion, Transfer, and StorageSystem to each other is shown. Specifically, FIG. 18A shows animplementation of the Integrated Energy Conversion, Transfer, andStorage System that includes a mechanical coupling, a variabledisplacement hydraulic rotational unit, a propulsion shaft, a highpressure accumulator and a low pressure accumulator. FIG. 18BA shows animplementation of an accumulator unit with hollow space for a propulsionshaft that provides a direct mechanical connection. In thisimplementation, the high pressure accumulator and a low pressureaccumulator surround the hollow space for the propulsion shaft.

Referring now to sectional views provided in FIGS. 19A, 19B, and 19C, insome implementations of the Integrated Energy Conversion, Transfer, andStorage System, the hydraulic unit acts as an integrated hydraulic powerand control unit, using vane type configuration of hydraulic pump andmotors. FIG. 19D shows a side view of the Integrated Energy Conversion,Transfer, and Storage System through which section cuts are made forFIGS. 19A, 19B, and 19C.

Referring now to exploded views provided in FIGS. 20 and 21, in someimplementations of the Integrated Energy Conversion, Transfer, andStorage System, the hydraulic unit acts as an integrated hydraulic powerand control unit, using vane type configuration of hydraulic pump andmotors.

Referring now to sectional views provided in FIGS. 22A, 22B, and 22C, insome implementations of the Integrated Energy Conversion, Transfer, andStorage System, the hydraulic unit acts as an integrated hydraulic powerand control unit, using vane type configuration of hydraulic pump andmotors. Additionally, FIG. 22D illustrates the mechanical flow path incontinuous arrows, and the hydraulic flow path in dashed arrows.

Referring now to isometric view provided in FIG. 23, the mechanical flowpath in the Integrated Energy Conversion, Transfer, and Storage Systemis shown in continuous arrows, and the hydraulic flow path in theIntegrated Energy Conversion, Transfer, and Storage System is shown indashed arrows.

As shown in FIG. 20, in some implementations of the Integrated EnergyConversion, Transfer, and Storage System, the integrated hydraulic powerand control unit includes connection flange 301 attached to joint 302and shaft 304, which is supported by bearing 303. The variabledisplacement hydraulic rotational unit uses a variable displacementhydraulic vane pump/motor implementation, and includes a fixed housing305 that is closed on the mechanical coupling side (towards connectionflange 301) by cap 313.

On the directional control valve side of the Integrated EnergyConversion, Transfer, and Storage System, the fixed housing 305 isclosed by directional control valve cap 321. Within fixed housing 305,the mobile housing 306 is positioned. The mobile housing 306 glideswithin fixed housing 305 due to the plane surface 307 that is machinedon the outer surface of mobile housing 306 and inner surface 319 of thefixed housing 305. The mobile housing 306 is moved due to guidancesurfaces 307 and 319 in one direction. The mobile housing 306 actuatedby pin 317 of solenoid 316 attached to the fixed housing 305 insideorifice 315. The mobile housing 306 is retracted in the initial positionby elastic element (spring) 318 placed inside orifice 314 of the fixedhousing 305.

As shown in the sectional view A-A in FIG. 19A, the inner surface of themobile housing 306 has an elliptical shape. In FIG. 19A, the mobilehousing 306 shown in a perpendicular view relative to the rotation axis.Within the mobile housing 306, rotor 308 is placed. The rotor 308 isrigidly connected to shaft 304. Inside the rotor 308 are gliding vanes309 and 310. Also within the rotor 308 are hydraulic feeding channels311 and 312, which function as hydraulic inlet/outlet ports, accordingto the position of the directional control valve and torque flow.

In some implementations of the of the Integrated Energy Conversion,Transfer, and Storage System, the hydraulic feeding channels 311 and 312are directed adjacent the vanes into the flow space, and are limited bythe vanes that glide inside the rotor 308, the outer rotor 308 surface,and the inner elliptical inner surface of the mobile housing 306. Due tothe difference of cross-sectional shape of the elliptical inner surfaceof the mobile housing 306 and the cylindrical outer surface of the rotor308, the volume is limited between the vanes, the mobile housing, androtor. The volume changes continuously during rotation of the rotor,which provides the variable displacement that is needed for the variabledisplacement hydraulic rotational unit. The magnitude of displacementvariability is continuously adjusted by the position of the mobilehousing 306 relative to the rotor 308. For concentric positioning ofmobile housing 306 and rotor 308 during the rotation of the rotor 308,no displacement variability is obtained, and no hydraulic/mechanicalenergy transfer is obtained. This condition is that is implemented whenthe recovery system should not interfere with the mechanicaltransmission of the vehicle.

In some implementations, the maximum variability of the displacement isobtained when the mobile housing 306 is moved to the most extremeposition allowed by the dimensions of the fixed housing 305. The mobilehousing 306 is moved by the pin 317 of the solenoid 316. The maximum andintermediate positions of the mobile housing 306 relative to the rotor308 are needed for hydraulic-mechanical energy conversion during systemoperation.

If a mechanical torque is applied, using the connection flange 301,joint 302, shaft 304, and rotor 308, then the liquid is absorbed throughthe hydraulic feeding channel 311 connected to the space that increasesduring the rotation of the rotor. The active volume is limited betweenthe vanes, mobile housing, and rotor. During further rotation, thevolume is limited between the vanes, mobile housing, and rotor. Thevolume decreases, forcing the liquid to exit the rotor through hydraulicfeeding channel 312. This is typical actuation for an implementationthat employs variable displacement hydraulic vane pump/motors.

In some implementations of the Integrated Energy Conversion, Transfer,and Storage System, the fixed housing 305 is closed on the directionalcontrol valve side by the connecting cap 321. The connecting cap 321separates the variable displacement hydraulic rotational unit and thedirectional control valve, which has two channels 332 and 333 alignedwith feeding channels 311 and 312. The connecting cap 321 supports therotational geared flow control element 322 which rotates, actuated bythe gear 323, which is powered by the rotational electric actuator 324.The rotational geared flow control element 322 defines a large sizehydraulic orifice 325, which during all rotational positions generatesthe connection to the low pressure accumulator. The smaller sizehydraulic orifice 326 of the rotational geared flow control element 322generates, by rotation, alternate connections to the fixed hydraulicports 328 for the high pressure accumulator. The alternate connectionsinclude port 329 for the direct connection pipe 152 (see FIG. 1) andport 330 for the connection to the thermal unit using the pipe 202 (seeFIG. 9). The fixed hydraulic ports 328, 329, 330, 331 are integrated inthe directional control valve housing 327.

Referring now to the directional control valves described in FIGS. 1-4B,the relationship of the ports with the embodiment described in FIGS.19A-21 is provided below. In some implementations, the feeding channels311 and 312 are permanently connected during rotation of rotor 308 withfixed channels 331 and 330, respectively.

In some implementations, Port A of rotational directional control valve110 and Port A′ of rotational directional control valve 140 (See FIGS.1-4B) are connected to hydraulic port 311 in rotor 308 and channel 332in connecting cap 321 (See FIGS. 20-21). In other implementations, PortB of rotational directional control valve 110 and Port B′ of rotationaldirectional control valve 140 (See FIGS. 1-4B) are connected tohydraulic port 312 in rotor 308 and channel 333 in connecting cap 321.In still other implementations, Port C of rotational directional controlvalve 110 and Port C′ of rotational directional control valve 140 (SeeFIGS. 1-4B) are connected to hydraulic port 329 in directional controlvalve housing 327. In yet other implementations, Port D of rotationaldirectional control valve 110 and Port D′ of rotational directionalcontrol valve 140 (See FIGS. 1-4B) are connected to hydraulic port 328in directional control valve housing 327. In at least oneimplementation, Port E of rotational directional control valve 110 andPort E′ of rotational directional control valve 140 (See FIGS. 1-4B) areconnected to hydraulic port 330 in directional control valve housing327. In some implementations, Port F of rotational directional controlvalve are connected to and Port F′ of rotational directional controlvalve 140 (See FIGS. 1-4B) for hydraulic port 331 in directional controlvalve housing 327.

The rotation of the control disc 322 generates the following flow paths:(1) Port A-Port C and Port B-Port D for charge/discharge of the highpressure accumulator with opposed rotational direction during dischargeas during charging; (2) Port A-Port D and Port B-Port C forcharge/discharge of the high pressure accumulator with same rotationaldirection during discharge as during charging; (3) Port A-Port E andPort B-Port D for hydrostatic propulsion mode in one rotationaldirection; (4) Port B-Port E and Port A-Port D for hydrostaticpropulsion mode in opposed rotational direction; (5) Port A-Port F andPort B-Port D for thermal energy recovery mode in one rotationaldirection; (6) Port B-Port F and Port A-Port D for thermal energyrecovery mode in opposed rotational direction; (7) Port A-Port D, PortB-Port D, and Port C closed for retarder mode (accumulator full).

Referring now to FIG. 24 an implementation of the Integrated EnergyConversion, Transfer, and Storage System is shown with an integratedaxial piston-variable displacement pump. The accumulator housing 338covering the high pressure accumulator 360 is closed by end cap 339. Tothe end cap 339 is attached housing 340 of the axial piston hydraulicunit which comprises of rotational control valve 342 actuated by gear341 which is powered by electrical rotational actuator 343. Therotational control valve 342 includes hydraulic orifices 344 and 352that provide a connection to the high pressure accumulator 360 or thelow pressure accumulator 353. The hydraulic orifices 344 and 352 arepositioned in alignment with hydraulic orifices 359 and 354 of the endcap 339. Piston body 345 contains pistons 346 that are placed parallelto and rigidly mounted on the propulsion shaft 355. The pistons 346 aresupported by rotational hemisphere 347 that is rotated around aperpendicular axis to propulsion shaft 355 by gear 348, which changesthe stroke of the pistons 346 and, thus, the displacement of thehydraulic unit. Propulsion shaft 355 has an attached connection flange350 and is mounted in the housing 340 using bearings 349 and 358. Therotational control valve 342 rotates against the propulsion shaft 355using bearings 351. To reduce the mass of the propulsion shaft 355, thepart that rotates inside separation wall 357 between the high pressureaccumulator 360 and the low pressure accumulator 353 includes a hollowpart 356.

Referring now to FIG. 25, an implementation of the Integrated EnergyConversion, Transfer, and Storage System that incorporates an axialpiston pump and multiple gear sets. Additional axial piston hydraulicunits can be included in a modular manner to increase the workingcapacity of Integrated Energy Conversion, Transfer, and Storage System.Specifically, FIG. 25 shows an implementation of the Integrated EnergyConversion, Transfer, and Storage System in which three hydraulic unitsare coupled by multiple gears to the main propulsion shaft. FIG. 26shows a sectional view of the implementation of the Integrated EnergyConversion, Transfer, and Storage System shown in FIG. 25. FIG. 26 showsthe details of the integration of the hydraulic power units with theassociated control valve and the accumulator unit front plate.

Referring now to FIG. 27, the structure of the energy control unit (ECU)of Integrated Energy Conversion, Transfer, and Storage System is shownwith double action functionality to meet the functions of converting,accumulating, storing, and releasing energy. The energy control unit(ECU) of Integrated Energy Conversion, Transfer, and Storage System mayoperate in retarder and variable hydrostatic transmission modes.

As shown in FIG. 28, the port connections provided represent differentrunning conditions. These port connections include: A, A′ correspondingwith Port to Hydraulic Unit Inlet/Outlet; B, B′ corresponding with Portto Hydraulic Unit Inlet/Outlet; C, C′ corresponding with Port to HighPressure Accumulator; D, D′ corresponding with Port to Low PressureAccumulator; and F, F′ corresponding with Port to Thermal Unit. FIG. 28also sets forth several running cases and running conditions, whichinclude: (1) Constant Speed—No Intermediate Storage; (2) IntermediateStorage; (3) Controlled Flow Resistance—Retarder Mode; (4) Usage ofStored Energy—Same Rotational Direction as During Filling; (5) Usage ofStored Energy—Same Rotational Direction as During Filling; (6)Stop/Go-Low Speed/Low Load-Power Boost; and (7) Additional HydraulicFlow Source.

Referring now to FIG. 29, in some implementations of the IntegratedEnergy Conversion, Transfer, and Storage System, two pressure valves PV1and PV2 are incorporated which connect the high pressure accumulatorwith the low pressure accumulator. In the implementation of FIG. 29, thetwo pressure valves PV1 and PV2 act as safety features. Additionally,the Integrated Energy Conversion, Transfer, and Storage System includesa pressure transducer connected to the high pressure accumulator. Thepressure transducer measures the load and filling degree, as well asserves as an input parameter for the control system.

Referring now to the accumulator portion of the Integrated EnergyConversion, Transfer, and Storage System, FIG. 30A illustrates asingle-sided accumulator 402 including a housing 404, a hydraulic piston406 positioned to compress an energy storage medium 408 within thehousing 404, and a hydraulic inlet/outlet port 410. In someimplementations, the energy storage medium 408 is a compressible gassuch as a nitrogen gas, such that the piston 406 and the energy storagemedium 408 act as a pneumatic spring within the housing 404. FIG. 30Billustrates a single-sided accumulator 412 including a housing 414, ahydraulic piston 416 positioned to compress a gaseous elastic element418, such as a nitrogen gas sealed behind the piston 416, and amechanical elastic element 420 such as a mechanical helical or discspring, and a hydraulic inlet/outlet port 422. The two elastic elements418 and 420 have different elasticities and different energy storagecapacities. The gaseous elastic element 418 is sealed within theaccumulator 412 at a pre-charge pressure. FIG. 30C illustrates across-sectional view of the accumulator 412 taken along line 1C-1C ofFIG. 30B.

FIG. 30D illustrates a single-sided accumulator 424 including a housing426, a hydraulic piston 428 positioned to compress a primary elasticelement 430 which includes an annular elastomer spring engaged with thepiston 428 and with an end of the housing 426 opposite the piston 428across a length of the primary elastic element 430, and a hydraulicinlet/outlet port 436. FIG. 30D also illustrates that the single-sidedaccumulator 424 includes two secondary elastic elements 432 and 434,which also include annular elastomer springs. The secondary elasticelements 432 and 434 are engaged with respective and opposite sides ofthe primary elastic element 430, and with respective and oppositesidewalls of the housing 426.

FIG. 30E illustrates a single-sided accumulator 438 including ahydraulic cylinder 440 having a central piston 442 positioned to slidelongitudinally through the cylinder 440. The accumulator 438 alsoincludes a primary elastic element 444 engaged with the piston 442 and aflexible end wall 446 of the accumulator 438 in a manner similar to thatdescribed above for the primary elastic element 430. The accumulator 438also includes two secondary elastic elements 448 and 450 engaged withthe primary elastic element 444 and flexible side walls 452 and 454 ofthe accumulator 438 in a manner similar to that described above for thesecondary elastic elements 432 and 434. The piston 442 glides or slideslongitudinally within the primary elastic element 44, compressing afluid therein. The flexible walls 446, 452, and 454 contain and help tocompress the respective elastic elements 444, 448, and 450. Theaccumulator 438 also includes a hydraulic inlet/outlet 456.

FIG. 31A illustrates a double-sided accumulator 458 including a housing460, a first inlet/outlet 462, a second inlet/outlet 464, a first piston466, a second piston 468, a single elastic element 470 comprising acompressed gas, and a dividing wall 472. In the double-sided accumulator458, the storage media of the two sides of the elastic element 470 areof same nature, that is, the same gaseous material, such as nitrogen.Displacement of the pistons 466 and 468 is limited inside the housing460 by the dividing wall 472, which nevertheless has an opening at thecenter thereof to allow the gaseous material to flow freely back andforth between the pistons 466 and 468.

FIG. 31B illustrates a double-sided accumulator 474 including a housing476, a first inlet/outlet port 478, a second inlet/outlet port 480, afirst piston 482, a second piston 484, a gaseous elastic element 486such as a nitrogen gas sealed behind and between the pistons 482 and484, and a mechanical elastic element 488 such as a mechanical helicalor disc spring or an elastomer hose. The gaseous elastic element 486 andthe mechanical elastic element 88 are fixed to and defined between thepistons 482 and 484.

FIG. 31C illustrates a double-sided accumulator 490 including a housing492, a first inlet/outlet port 494, a second inlet/outlet port 496, afirst piston 498, a second piston 500, a primary elastic element 502,and two secondary elastic elements 504 and 506. The primary andsecondary elastic elements 502, 504, 506 each comprise an elastomerelement or a mechanical spring. The primary and secondary elasticelements 502, 504, 506 are arranged in parallel. Otherwise stated, theprimary and secondary elastic elements 502, 504, 506 are each coupled ata first end to the first piston 498 and at a second end to the secondpiston 500, such that the primary elastic element 502 is confinedbetween the first and second pistons 498 and 500 and the two secondaryelastic elements 504 and 506, and such that the secondary elasticelements 504 and 506 are confined between the first and second pistons498 and 500, the primary elastic element 502, and a sidewall of thehousing 492.

FIG. 31D illustrates a double-sided accumulator 108 including a housing510, a first inlet/outlet port 512, a second inlet/outlet port 514, afirst piston 516, a second piston 518, a primary elastic element 520,and two secondary elastic elements 522 and 524. The primary andsecondary elastic elements 520, 522, 524 each comprise an elastomerelement or a mechanical spring. The primary and secondary elasticelements 520, 522, 524 are arranged in series. Otherwise stated, theprimary elastic element 520 is confined between two sidewalls of thehousing 510 and the two secondary elastic elements 522 and 524, and thesecondary elastic elements 522 and 524 are confined between a respectiveone of the first and second pistons 516 and 518, the primary elasticelement 520, and the two sidewalls of the housing 510.

FIG. 32A illustrates a double-sided accumulator 526 with parallel andintegrated high-pressure and low-pressure accumulators 528 and 530,respectively, including an outer housing 532 and an internal dividingwall 534 that divides the accumulator 526 between the high-pressureaccumulator 528 and the low-pressure accumulator 530. The accumulator526 includes a first inlet/outlet port 536 for the high-pressureaccumulator 528, a second inlet/outlet port 538 for the high-pressureaccumulator 528, a third inlet/outlet port 540 for the low-pressureaccumulator 530, and a fourth inlet/outlet port 542 for the low-pressureaccumulator 530. The high-pressure accumulator 528 includes an elasticelement 544, which includes an elastomer hose, pre-filled andpre-charged with a compressed nitrogen gas.

FIG. 32B illustrates a double-sided accumulator 546 with parallel andintegrated high-pressure and low-pressure accumulators 548 and 550,respectively, including an outer housing 552 and an internal dividingwall 554 that divides the accumulator 546 between the high-pressureaccumulator 548 and the low-pressure accumulator 550. The accumulator546 includes a first inlet/outlet port 556 for the high-pressureaccumulator 548, a second inlet/outlet port 558 for the high-pressureaccumulator 548, a third inlet/outlet port 560 for the low-pressureaccumulator 550, and a fourth inlet/outlet port 562 for the low-pressureaccumulator 550. The high-pressure accumulator 548 includes a firstpiston 564, a second piston 566, and an elastic element 568 positionedbetween and coupled to the first and second pistons 564 and 566.

FIG. 32C illustrates possible cross-sectional shapes of components ofthe accumulator 546, taken along line 3C,3D-3C,3D of FIG. 32B, whereinthe high-pressure accumulator 548 has a circular cross-sectional shapeand the low-pressure accumulator 550 has a cross-sectional shapecomprising a crescent, or elliptical cross-sectional shape with aportion blocked by the circular cross-sectional shape of thehigh-pressure accumulator 548. FIG. 32D illustrates possiblecross-sectional shapes of components of the accumulator 546, taken alongline 3C,3D-3C,3D of FIG. 32B, wherein the high-pressure accumulator 548has a circular cross-sectional shape and the low-pressure accumulator550 has a trapezoidal cross-sectional shape with a portion blocked bythe circular cross-sectional shape of the high-pressure accumulator 548.

FIG. 33A illustrates a double-sided accumulator 570 with parallel,integrated, and concentric high-pressure and low-pressure accumulators572 and 574, respectively, including an outer housing 576 and aninternal dividing wall 578 that divides the accumulator 570 between thehigh-pressure accumulator 572 and the low-pressure accumulator 574. Thehigh-pressure accumulator 572, the low-pressure accumulator 574, theouter housing 576, and the internal dividing wall 578 have circularcross-sectional shapes, and the internal dividing wall 578 is concentricwith the outer housing 576.

The accumulator 570 includes a first inlet/outlet port 580 for thehigh-pressure accumulator 572, a second inlet/outlet port 582 for thehigh-pressure accumulator 572, a third inlet/outlet port 584 for thelow-pressure accumulator 574, and a fourth inlet/outlet port 586 for thelow-pressure accumulator 574. The low-pressure accumulator 574 includesa first elastic element 588 and a second elastic element 590, whichstore energy when deformed under high or low pressures. In someimplementations, the internal dividing wall 578 is elastic orelastomeric to retain stored energy when deformed under high or lowpressures.

FIG. 33B illustrates a double-sided accumulator 592 with parallel andintegrated high-pressure and low-pressure accumulators 594 and 596,respectively, including an outer housing 598 and an internal dividingwall 600 that divides the accumulator 592 between the high-pressureaccumulator 594 and the low-pressure accumulator 596. The accumulator592 includes a first inlet/outlet port 202 for the high-pressureaccumulator 594, a second inlet/outlet port 604 for the high-pressureaccumulator 594, a third inlet/outlet port 606 for the low-pressureaccumulator 596, and a fourth inlet/outlet port 608 for the low-pressureaccumulator 596. The high-pressure accumulator 594 includes a firstpiston 610, a second piston 612, and an elastic element 614 positionedbetween the first and second pistons 610 and 612. The elastic element614 includes a liquid/gas mixture with continuously variable storagecapacity for liquid and gas in varying proportions, wherein thecomposition of the liquid/gas mixture is controlled by an externalhydraulic circuit.

FIG. 34 illustrates a schematic diagram of a double sided accumulator616 coupled at its first side to a first flow control valve 618 and atits second side to a second flow control valve 620. The first and secondflow control valves 618 and 620 are coupled, respectively, to a firsthydraulic motor 622 that powers a first mechanical device such as awheel 624, and to a second hydraulic motor 626 that powers a secondmechanical device such as a wheel 628. The accumulator 616 has animplementation matching that described above for accumulator 126 and/oraccumulator 146, that is, the accumulator 616 is a double sidedaccumulator with parallel and integrated high-pressure and low pressureaccumulators 630, 632, respectively.

The first and second flow control valves 618 and 620 couple hydraulicports of the accumulator 616 to hydraulic ports of the hydraulic motors622 and 626, to allow hydraulic fluid to flow from the accumulator 616to the motors 622 and 626, to discharge energy from the accumulator 616to drive the wheels 624 and 628, or to allow hydraulic fluid to flowfrom the motors 622 and 626 to the accumulator 616, to recover energyfrom the wheels 624 and 628 and store it in the accumulator 616. In suchan implementation, the accumulator 616 independently recovers energyfrom, or provides energy to, the wheels 624 and 628, improving overallefficiency.

FIGS. 35A, 35B, 36A, 36B, and 37A-37E illustrate more specific detailsof one implementation of the accumulator 616. FIGS. 35A, 35B, 36A, and36B illustrate that the accumulator 616 includes a hollow, cylindricalouter housing 634, a first end cap 636 at a first end of the housing634, a second end cap 638 at a second end of the housing 634 opposite tothe first end, and an internal dividing wall 640 that separates thehigh-pressure accumulator 630 from the low-pressure accumulator 632within the housing 634. FIGS. 35A, 35B, 36A, and 36B also illustratethat the accumulator 616 includes a hydraulic pipe 642 that extendsthrough and along the length of the high-pressure accumulator 630. FIG.35B also illustrates that the second end cap 638 includes a low pressureport 644 that is hydraulically coupled to the low-pressure accumulator632, two high pressure ports 646 that are hydraulically coupled to thehigh-pressure accumulator 630, and a hydraulic pipe port 648 that ishydraulically coupled to the hydraulic pipe 642. The hydraulic pipe 642can extend along the length of the accumulator 616 to couple the firstflow control valve 618 directly to the second flow control valve 620.

FIGS. 36A, 36B, and 37A-37E illustrate that the accumulator 616 includesan elastic element 650, which includes an elastomer hose pre-filled andpre-charged with a compressed nitrogen gas, positioned within thehigh-pressure accumulator 630. FIGS. 36A, 36B, and 37A-37E illustratethat the accumulator 616 also includes gaskets 652 to seal the first andsecond end caps 636 and 638 to the end faces of the housing 634.

FIG. 38A illustrates a schematic diagram of a double sided accumulator654 coupled at its first side to a first flow control valve 656 and atits second side to a second flow control valve 658. The first and secondflow control valves 656 and 658 are coupled, respectively, to a firsthydraulic motor 660 that powers a first mechanical device such as awheel 662, and to a second hydraulic motor 664 that powers a secondmechanical device such as a wheel 666. The accumulator 654 has animplementation matching that described above for accumulator 616 exceptfor the differences described herein.

As illustrated in FIGS. 38B and 38, the accumulator 654 includes aninternal dividing wall 668 similar to the internal dividing wall 640,but has an open conduit 670 extending longitudinally therethrough. Asillustrated in FIG. 38B, a propulsion shaft or axle 672 extends throughthe open conduit 670. The axle 672 is coupled, such as rigidly coupled,to the first wheel 662 by a first mechanical coupling 674, and iscoupled, such as rigidly coupled, to the second wheel 666 by a secondmechanical coupling 676. Thus, the two wheels 662 and 666 are rigidlycoupled to one another by an axle 672 extending through the accumulator654. FIGS. 39A-39C further illustrate the accumulator 654, including itsdividing wall 668 and axle 672, as well as additional details of theflow control valve 656, including its actuation mechanism 678.

FIGS. 40A and 40B illustrate another double-sided accumulator 680coupled at its first side to a first flow control valve, a firsthydraulic motor, and a first mechanical coupling 682 and at its secondside to a second flow control valve, a second hydraulic motor, and asecond mechanical coupling. The accumulator 680 has an implementationmatching that described above for accumulator 654 except for thedifferences described herein. The accumulator 680 has an overallcross-sectional shape comprising an ellipse, with an internal dividingwall 686 extending along the major axis of the ellipse. The accumulator680 also includes a plurality of elastomeric elements 684 for storage ofaccumulated energy.

FIGS. 41A-41G illustrate sets of multiple accumulators that areintegrated with one another and with respective valves, hydraulicmotors, and axles as described herein, and provided together as anintegrated set of multiple accumulators. FIG. 41A illustrates aschematic diagram of such an integrated set 688 of six accumulators 690,together with respective valves, hydraulic motors, and axles, whereineach of the six accumulators 690 has a structure corresponding to thatof the accumulator 654. The axle of each of the six accumulators 690 iscoupled at either end to a gear 692. The six accumulators 690 aregrouped into accumulator units or subsets of three accumulators 690,with each of the units or subsets housed together within a housing 694having an elliptical cross-sectional shape.

The gears 692 coupled to the axle of each accumulator 690 within asingle one of the housings 694 are meshed with one another, such thatthe three accumulators in each housing 694 are coupled to one another inparallel. Further, the axle of one of the accumulators within each ofthe housings 694 is coupled at either end to a mechanical coupling 696.One mechanical coupling 696 coupled to one of these axles is coupled toanother mechanical coupling 696 coupled to the other of these axles,such that the accumulators of the two accumulator units or subsets arecoupled to one another in series.

FIGS. 41B-41G illustrate another accumulator unit 698 including a singlehigh-pressure accumulator 700 and a single low-pressure accumulator 702,housed together within a housing 704 having an ellipticalcross-sectional shape. The accumulator unit 698 is coupled at each ofits two opposing ends to three valves 706 and three hydraulic motors708. Each of the hydraulic motors 708 is coupled to a respective gear710 and the three gears 710 are meshed with one another to couple thevalves 706 and motors 708 to one another in parallel. The accumulatorunit 698 may be used in place of one or both of the accumulator units orsubsets of three accumulators 690 illustrated in FIG. 41A.

FIG. 42A is illustrates a three-dimensional model of a hydrauliccylinder 4230 in the hydraulic propulsion system 4200. As illustrated inFIG. 42A, the hydraulic cylinder 4230 includes a first inlet/outlet4250, and second inlet/outlet 4252, a third inlet/outlet 4254, and afourth inlet/outlet 4256. Depending on the positions of the first andsecond flow control valves 4220 and 4222, the hydraulic cylinder 4230has either a first inlet 4250, a second inlet 4252, a first outlet 4254,and a second outlet 4256, or a first inlet 4254, a second inlet 4256, afirst outlet 4250, and a second outlet 4252.

The hydraulic cylinder 4230 illustrated in FIG. 42A houses a fixeddividing wall 4240, which divides the hydraulic cylinder 4230 into twodistinct and rigid hydraulic chambers. Each hydraulic chamber is itselfdivided into two sub-chambers that are separated by additional dividingwalls 4241. A first one of the chambers houses a first piston 4242 and afirst elastic element or spring 4244 coupled to the first piston 4242and to the dividing wall 4240 in its first sub-chamber, as well as athird piston 4243 and a third elastic element or spring 4245 coupled tothe third piston 4243 and to a wall opposite the dividing wall 4240 inits second sub-chamber. A second one of the chambers houses a secondpiston 4246 and a second elastic element or spring 4248 coupled to thesecond piston 4246 and to the dividing wall 4240 in its firstsub-chamber, as well as a fourth piston 4247 and a fourth elasticelement or spring 4249 coupled to the fourth piston 4247 and to a wallopposite the dividing wall 4240.

The hydraulic cylinder 4230 illustrated in FIG. 42A includes a dilatingfluid that flows into and out of the hydraulic cylinder 4230 through thefirst inlet/outlet 4250 and the second inlet/outlet 4252, and a workingfluid that flows into and out of the hydraulic cylinder 4230 through thethird inlet/outlet 4254 and the fourth inlet/outlet 4256. The workingfluid is separated from the dilating fluid within the hydraulic cylinder4230 by the first and second pistons 4242 and 4246.

When relatively high-pressure waves travelling through the dilatingfluid enter the hydraulic cylinder 4230 through the first and secondinlets 4250 and 4252, they travel toward and then exert relatively highpressures against the first and second pistons 4242 and 4246. As aresult, the pistons 4242 and 4246 are urged to move toward the workingfluid, compress the first and second springs 4244 and 4248, and initiaterelatively high-pressure waves that travel through the working fluidtoward the third and fourth pistons 4243 and 4247 and the third andfourth springs 4245 and 4249. The high pressure waves compress thesprings 4245 and 4249 and travel toward the outlets 4254 and 4256 toexit the hydraulic cylinder 4230 through the outlets 4254 and 4256.

When relatively high-pressure waves travelling through the working fluidenter the hydraulic cylinder 4230 through the inlets 4254 and 4256, theytravel toward and then exert relatively high pressures against the thirdand fourth pistons 4243 and 4247, third and fourth springs 4245 and4249, and first and second pistons 4242 and 4246. As a result, thesprings 4245 and 4249 are compressed, the springs 4244 and 4248 areextended, and the pistons 4242 and 4246 are urged to move toward thedilating fluid to initiate relatively high-pressure waves that travelthrough the dilating fluid toward the outlets 4250 and 4252 to exit thehydraulic cylinder 4230 through the outlets 4250 and 4252.

Thus, as the first and second flow control valves 4220 and 4222 aremoved back and forth between their respective first and secondpositions, and as the relatively high-pressure waves alternate betweenentering the hydraulic cylinder 4230 through the inlets 4250 and 4252and through the inlets 4254 and 4256, the pistons 4242 and 4246 eachbegin to oscillate back and forth within the hydraulic cylinder 4230with respect to the fixed dividing wall 4240. The springs 4244 and 4248are alternately compressed and extended. In some implementations, thismovement of the springs 4244 and 4248 provides sonic inertia and/orintroduces a phase shift into the system's dynamic behavior. Further, asthe relatively high-pressure waves travel back and forth through thehydraulic cylinder 4230, the springs 4245 and 4249 are increasinglycompressed, which in some implementations provides energy storage (e.g.,accumulation) in the compression of the springs 4245 and 4249. Themasses of the pistons 4242, 4246, 4243, and 4247, and the springconstants or stiffness of the springs 4244, 4245, 4248, and 4249 areselected or designed so that these components oscillate under resonantconditions, or resonate, within the hydraulic cylinder 4230 for a givenfrequency or given frequencies of the relatively high-pressure waves.

FIG. 42B illustrates a hydraulic system 712 including a hydrauliccylinder 714 and a hydraulic accumulator 732. In the hydraulic system712, a hydraulic flow control valve 716 is used to generate oscillatinghydraulic pressure waves travelling through opposed hydraulic conduits720 and 722. A constant-flow hydraulic pump 724 generates and provides ahigh-pressure hydraulic fluid to the first flow control valve 716, and ahydraulic fluid reservoir 726 provides a relatively low-pressurehydraulic fluid to the first flow control valve 716.

FIG. 42C illustrates a cross-sectional view of an alternativeaccumulator unit 4540, which acts as a dual high-pressure andlow-pressure accumulator unit by incorporating both the high-pressureaccumulator 4264 and the low-pressure accumulator 4266. The accumulatorunit 4540 includes a first inlet port 4542 that allows access for arelatively high-pressure fluid to the high pressure accumulator 4264,and a second inlet port 4544 that allows access for a relativelylow-pressure fluid to the low pressure accumulator 4266. When ahigh-pressure fluid is provided to the high-pressure accumulator 4264through the first inlet 4542 and/or a low-pressure fluid is provided tothe low-pressure accumulator 4266 through the second inlet 4544, therespective pressures turn a piston 4546 within the accumulator 4540.This compresses a plurality of disc springs 4548 and a plurality ofhose-type elastomer springs 4550 interconnected with the disc springs4548, thereby storing energy for later use in the compression of thesprings 4548, 4550.

In one implementation, the springs 4548 and 4550 are mounted on asupport shaft 4552 running the length of the accumulator 4540, toprovide support and stability for the springs 4548 and 4550. In someembodiments, the accumulator 4540 includes a plurality of massive bodies4554 coupled to the springs 4548 and/or 4550. The accumulator 4540 iscoupled to a hydraulic conduit of the hydraulic propulsion system 4200that carries oscillating pressure waves, as described herein, so thatthe accumulator 4540 can also store energy in the oscillation of themasses 4554 and the springs 4548, 4550. Spring constants or stiffnessesof the springs 4548 and 4550 and/or the masses of the massive bodies4554 are selected or designed so that these components oscillate underresonant conditions, or resonate, within the accumulator 4540.

FIG. 42D illustrates a cross-sectional view of an alternativeimplementation of an accumulator unit 4556, which acts as a dualhigh-pressure and low-pressure accumulator unit by incorporating boththe high-pressure accumulator 4264 and the low-pressure accumulator4266. The accumulator unit 4556 has the same features as the accumulatorunit 4540, except that it includes a third inlet port 4558 that allowsaccess for a relatively high-pressure fluid to the high pressureaccumulator 4264, a fourth inlet port 4560 that allows access for arelatively low-pressure fluid to the low pressure accumulator 4266, anda second piston 4562 coupled to the springs 4548 and 4550 at an endthereof opposite to the piston 4546.

When a high-pressure fluid is provided to the high-pressure accumulator4264 through the first inlet 4542 and/or the third inlet 4558, and/or alow-pressure fluid is provided to the low-pressure accumulator 4266through the second inlet 4544 and/or the fourth inlet 4560, therespective pressures move the pistons 4546 and/or 4562 within theaccumulator 4540, thereby compressing the springs 4548 and/or 4550, andstoring energy for later use in the compression of the springs 4548,4550 and/or in resonance of the springs 4548, 4550 and pistons 4546,4562.

A variable speed electric motor is used to actuate the valve 716, suchas by moving a rotor therein, to either couple the pump 724 to the firstconduit 720 and the reservoir 726 to the second conduit 722, or couplethe pump 724 to the second conduit 722 and the reservoir 726 to thefirst conduit 720. The electric motor is used to actuate the valve 716to alternate between these two positions, to create oscillating pressurewaves within the conduits 720 and 722 that are phase shifted from oneanother by 180 degrees.

As the oscillating pressure waves travel through the conduits 720 and722, they encounter a first piston 728 and a second piston 730,respectively, within the hydraulic cylinder 714, as well as a thirdpiston 734 and a fourth piston 736, respectively, within the hydraulicaccumulator 732. The first and second pistons 728 and 730 are rigidlycoupled to one another and form a single hollow cylindrical structure744, or a hollow shaft with closed ends, such that they move back andforth in unison within the hydraulic cylinder 714. The hollowcylindrical structure 744 includes two opposed longitudinal grooves orslots 738 hydraulically coupled to respective orifices 740 and 742 inthe hydraulic cylinder 714, which allow hydraulic fluid or hydraulic oilto be pumped into or out of the hollow cylindrical structure 744, tochange the overall or total mass of the hollow cylindrical structure744. Hydraulic fluid is provided to the orifices 740 and/or 742 by ahydraulic pump 756, a flow control valve 758, and a connection port 760.

As the oscillating pressure waves encounter the first and second pistons728, 730, they cause the hollow cylindrical structure 744, including thepistons 728 and 730, to oscillate back and forth within the hydrauliccylinder 714. The amplitude of this oscillation is limited by a set ofelastomeric stops 746 positioned near the ends of the hydraulic cylinder714. In this way, the hydraulic cylinder 714 provides the hydraulicsystem 712 with hydraulic inertia, the magnitude of which is controlledby pumping hydraulic fluid into or out of the hollow cylindricalstructure 744.

The hydraulic accumulator 732 includes a first spring 748, coupled at afirst end thereof to the third piston 734 and at a second end thereofopposite to the first end to a fifth piston 752. The hydraulicaccumulator 732 also includes a second spring 750, coupled at a firstend thereof to the fourth piston 736 and at a second end thereofopposite to the first end to a sixth piston 754. The fifth and sixthpistons 752 and 754 are hydraulically linked to one another by asecondary hydraulic cylinder 762. The positions of the fifth and sixthpistons 752 and 754 is controlled, such as to control the energy storagecapacity of the springs 748 and 750, by pumping hydraulic fluid into orout of the secondary hydraulic cylinder 762, such as by the hydraulicpump 756 and a flow control valve 764.

As the oscillating pressure waves encounter the third and fourth pistons734 and 736, they cause the springs 748 and 750 to oscillate back andforth within the hydraulic accumulator 732, such as between extended andcompressed states. The amplitude of this oscillation is limited by a setof elastomeric stops 766 positioned near the ends of the hydraulicaccumulator 732. In this way, the hydraulic accumulator 732 provides thehydraulic system 712 with hydraulic capacity or energy storage, in theform of the oscillating pistons 734 and 736 and springs 748 and 750, themaximum capacity of which is controlled by pumping hydraulic fluid intoor out of the secondary hydraulic cylinder 762.

Referring now to a fluid thermal unit component of the Integrated EnergyConversion, Transfer, and Storage System, FIG. 43 shows the generalstructure of a fluid thermal unit, according to one or moreimplementations of the present disclosure. In some implementations, thefluid thermal unit is capable of transferring thermal energy to a fluidvia a fluid heating interface. Sources of thermal energy include forexample, fuel embedded energy, solar energy, electrical energy, or awaste heat source. The heated fluid may be, for example, a hydraulicfluid having properties that cause the hydraulic fluid to expand whenheated.

In at least one implementation, one or more fuels provided by acorresponding fuel system are mixed with air and generates, due tocombustion, hot gases inside a combustion chamber. The hot gases may beused to heat a fluid inside a heat exchanger using heat transfer acrossa thermally conductive barrier that separates the hot gases from thefluid. Multiple fuels can be used simultaneously to heat the fluid,wherein the combustion gases produced by the different fuels are mixed.

Concurrently, within the combustion chamber, which is a separate workingspace dedicated to fuel combustion, primary emission reduction methodsmay be employed. Such emission reduction methods may include, forexample, one or more of water/steam injection and ultrasound excitationof combustion air. In some implementations, after thermal energy istransferred to the fluid via a heat exchanger device (e.g., heatinginterface), the combustion gases may be further treated to reduceemissions, using for example, a catalytic converter. The treatedcombustion gases are then released to the environment through an exhaustsystem.

The system shown in FIG. 43 enables technological improvements thatinclude: a low pressure combustion that is naturally a low-emissionprocess; and a possibility of having a separate device dedicated tooptimize the individual processes of combustion and heat transfer. Sucha separate device may feature, for example, an ultrasound generator toenhance combustion inside an ultrasound field, or geometrical shapesthat enhance convection and sound generation.

In some implementations of the Integrated Energy Conversion, Transfer,and Storage System, the fluid heating interface itself can be heateddirectly. Such methods for direct heating include, by way of exampleonly, and not by way of limitation: electrical heating, heating byexposure to solar radiation, heating by exposure to waste heat fromvarious sources (e.g., industrial waste heat, or combustion exhaustgases), or heating by exposure to other systems that generate heatduring operation (e.g., power electronic devices, hydraulic motor, orelectrical motors). According to the nature of the waste heat, heattransfer to the fluid interface may occur by conduction, radiation, orconvection.

FIG. 44 illustrates one implementation of a combustion chamber andcross-flow heat exchanger, for use with the fluid thermal unit of theIntegrated Energy Conversion, Transfer, and Storage System. In someimplementations, combustion air enters the cross-flow heat exchangerthrough an inlet port 802, while a fuel injector 804 directs fuel to theheat exchanger via the inlet port 802. Combustion is initiated by anigniter 806. Hot gases flow around one or more heat exchange tubes 808so that, during combustion, heat is transferred from the hot gases tothe heat exchange tubes 808. In at least one implementation, thestructure of heat exchange tubes 808 includes a thermally conductivepipe having perpendicular fins. After heat exchange occurs, thecombustion gases exit the heat exchange space through an exhaust outletport 810. Along a combustion gas flow path between the inlet port 802and the exhaust outlet port 810, the hot gas is bounded by thermallyconductive plates 812 coupled to the heat exchange tubes 808 so that asthe heat exchange tubes 808 are heated, heat is conducted to thethermally conductive plates 812.

Transverse to the general direction of gas flow, cold fluid is directedthrough the heat exchanger via a transverse fluid conduit. The coldfluid enters the heat exchange tubes 808 through a fluid inlet port 814and a fluid inlet chamber 816. The fluid inlet chamber 816 contains thefluid to be heated. The fluid inlet chamber 816 is in direct thermalcontact with the thermally conductive plates 812 to begin heating thecold fluid. In some implementations, one of the thermally conductiveplates 812 forms a wall in the fluid inlet chamber 816. The cold fluidflows from the fluid inlet chamber through (and is in direct contactwith) an inner face 818 of the heat exchange tube 808 so that the fluidabsorbs heat of combustion via the heat exchange tubes 808. The heatedfluid is then collected inside a fluid outlet chamber 820 and directedto a heat exchanger outlet port 822. The fluid outlet chambers 820 arebounded by thermally conductive panels 824 and 826.

Referring now to FIG. 45, an implementation of a fuel injector is shown.The fuel injector 902 is combined with an ultrasound generator in orderto assure proximity of the fuel jets to an ultrasound field that fostersmixing and a low emission combustion process. Air enters the fuelinjector 902 via an air inlet port 804. The air stream is reflectedinside the cavity 910 due to the annular tube 908, generating ultrasoundwaves that exit the injector through air outlet ports 906. Fuel enteringthe injector at port 912 is guided through the circular pipe 914 towardthe fuel outlet orifices 916. Part of the inlet air that has entered theinjector through air inlet port 904, passes through channel 918 to thecavity 920, where the pin 924 defines the shape of the reflectingcavity. The reflecting cavity is where air pressure waves are generatedthat exit the injector through the orifice 920. In some implementations,fuel is directed inside the injector through orifice 926. The circularpipe 928 feeds the fuel injection orifices 930. Accordingly to the heatexchanger functionality displayed in FIG. 46, the injector device thatis able to induce ultrasound waves in the combustion field, as shown inFIG. 45.

Referring now to FIG. 46, in some implementations of the IntegratedEnergy Conversion, Transfer, and Storage System, a fluid thermal unitrelies on the heating of the fluid using combustion gases. Air providedthrough an air filter 1002 is pushed by the fan 1004, through an airtrumpet 1006 to generate an ultrasound field inside the combustion zone,in accordance with the implementation described in FIG. 45. Fuel isprovided by a fuel injector 1008 and ignited by a spark igniter 1010.Inside the heat exchange portion of the fluid thermal unit, which isbounded by a housing 1012, is placed a coil 1014 that has fins on itsoutside surface to increase heat transfer from the hot gases to a fluidthat is flowing through the coil 1014. The heat transfer functionalityis employed using convection from the gases to the coil surface,conduction through the coil material, and convection from the coilmaterial to fluid flowing within the coils 1014. Exhaust gases aredirected through the exhaust system 1016 to the environment.

Referring now to FIG. 47A, the design of the gas flow inside the fluidunit thermal addresses pressure losses through the pipes, as identifiedby an exemplary simulation run. Referring now to FIG. 47B, a seconddesign consideration is also based on fluid flow analysis, which isrelated to the turbulence and velocity field near the coils and fins, toincrease the convection coefficient and consequently the heattransferred from the gas to the coil material. Referring now to FIG.47C, a third design consideration is related to vibrations of the air,and consequently to sound generated by the gas as it changes flowdirection and magnitude when flowing inside the housing of the fluidthermal unit and between the spaces of the coils. Notably, FIG. 47Dshows that the pressure loss, turbulence, intensity, and noise levels,given in decibels (dB), are shown to be in an acceptable range for atechnical application of 30 kW.

Referring now to FIG. 48, a generic fuel system 1100 is shown that feedsfuel to a fluid thermal unit. The fuel system 1100 is designed to usemultiple different fuels. The fuel system 1100 includes a liquid fueltank 1102, a fuel pump 1104, and a liquid metering device 1106. The fuelpump 1104 drives fuel from the liquid fuel tank 1102, through the liquidmetering device 1106, to a liquid fuel injector 1108 to prepare theliquid fuel for combustion inside a combustion chamber 1110. Thecombustion chamber 1110 may take the form of, for example, thecross-flow heat exchanger implementation shown in FIG. 44, or the heatexchanger implementation shown in FIG. 46. In at least oneimplementation, the fuel system 1100 may further include a gaseous fueltank 1112, a pressure-reducing valve 1114, and a gas metering device1116. A gaseous fuel stored under pressure in the gaseous fuel tank 1112flows through the pressure-reducing valve 1114 and the gas meteringdevice 1116, to a gas fuel injector 1118 placed inside the combustionchamber 1110.

As shown in FIG. 49, continuous combustion applies various emissionreduction measures to the fluid thermal unit, according to someimplementations. The emission reduction measures may be applied at anemission generation stage, at a combustion gas after-treatment stage, orat both stages. In some implementations, an ultrasound generator for theinlet air and combustion gases allows combustion to occur inside anultrasound field, which stimulates reactivity at a molecular level thatcorresponds to the ultrasound wave length. Additional air is added tothe combustion chamber to cool the combustion gases and reduce nitrogenemissions. Furthermore, injection of water or steam, as well as the useof a radiative burner, allows burning the fuel at lower combustiontemperature than an open flame, which reduces emissions. The addition ofa hydrogen-oxygen mixture from an external electrolyze may reducegeneral fuel consumption and emissions by generating heat of combustionwithout using atmospheric air. This is a method for short term,ultra-low emission operation of a combustion process.

Urea injection is an established oxides-of-nitrogen (NOx) reductionmethod applicable also to the fluid thermal unit together withstate-of-the-art post-combustion gas treatment devices such as, forexample, catalyzers, particle filters, and gas traps. An overview of theemission reduction effects of the arrangement shown in FIG. 49 isprovided in tabular form in FIG. 50.

Referring now to FIGS. 51A, 51B, a radiative burner is shown forincorporation into the fluid thermal unit, according to at least oneimplementation. In some implementations, a radiative burner provides aporous medium (e.g., a wire mesh) in which fuel may be burned at a lowercombustion temperature, at about 900 C, than in a conventionalopen-flame burner, which typically operates at about 1200 C.Consequently, nitrogen oxide emissions are much lower.

The fluid thermal unit that is equipped with such a radiative burnerprovides an air inlet path 1202, a burner distribution channel 1204, oneor more radiative burners 1206, an exhaust collector 1208, an exhaustpipe 1210, and fluid panels 1212. The distribution channel 1204 directsair and fuel into the radiative burners 1206, coupled thereto. In someimplementations, the radiative burners 1206 have a planar shape thatprovides optimal exposure for radiative heat transfer to the fluidpanels 1212 during combustion. Preferably, the fluid panels 1212 aresubstantially aligned with one another and are interdigitated with theradiative burners 1206 in order to capture radiation from both sides ofthe radiative burners 1206. Gaseous products of combustion are collectedby an exhaust collector 1208 and exit the radiative burner through anexhaust pipe 1210. The fluid panels 1212 by design have a large surfaceand low thickness for the fluid volume, in order to have large exposureof fluid panel surfaces 1212 a and 1212 b, to heat radiation. Fluid tobe heated enters the fluid panels 1212 through the inlet pipes 1214,1216. Hot fluid exits the fluid panels 1212 via the outlet ports 1216.

Referring now to FIGS. 52A, 52B, a hybrid design of a fluid thermal unitis shown in which a working fluid is heated using both the heat ofcombustion and an electrically-powered heat source, according to atleast one implementation. As shown in FIG. 52A, the hybrid fluid thermalunit includes an air inlet path 1302 and a fuel supply pipe 1304 thatfeeds fuel injectors 1306. Gases produced by combustion within acombustion chamber 1308 placed inside a housing 1310 are directed tooutlet pipe 1318. The hot gases transfer heat to a heater body 1312 thatheats up the fluid in the fluid workspace 1322 and the helical flow path1324, resulting by the helical fin 1326. The fluid enters the describedheating path via an inlet pipe 1320 and leaves the heating path throughthe outlet pipe 1328. The workspace is closed by an end cap 1340 fixedto the housing 1310. The helical fin 1326 is fixed to the electricalheater housing 1330 which contains an electrical resistor 1332, coupledto an electrical power supply 1318 by electrical wires 1334. Electricalpower to the hybrid thermal unit is regulated by an electricalcontroller 1336.

As shown in FIG. 53, a hybrid combustion-based and electrical heater isshown that is implemented as an add-on to the fluid thermal unitdescribed with respect to FIG. 46. The fluid coils 1470 are surroundedby an electrical radiative panel 1420 that has a cylindrical shape. Theelectrical radiative panel 1420 is coupled to an electrical power supply1430 via wires 1440, and an electrical control system 1450.

Referring now to FIG. 54, an exemplary waste heat harvesting apparatus1500 is shown for use in harvesting energy from a system that produceswaste heat carried by a fluid. The waste heat harvesting apparatus 1500includes a waste heat carrying fluid pipe 1510 and housing 1520. A heattransfer and flow path for a working fluid enters the housing 1520through pipe 1540 and leaves the housing 1520 using a pipe 1530. Auni-directional circuit from inlet to outlet is assured by a controlvalve 1550.

Referring now to FIG. 55, an implementation of the insulation componentis shown that improves heat transfer in the waste heat harvestingapparatus of FIG. 54. A gas flows through an internal space 1610 insidea thermally conductive pipe 1620. The thermally conductive pipe 1620 isin contact with a surrounding fluid 1630 flowing inside pipe 1640. Pipe1640 and housing 1660 thus create a space for an insulation material1650 to be inserted therebetween.

As shown in FIG. 56, in some implementations, an alternative heattransfer improvement device is incorporated into the system thatincludes heat transfer fins 1710 formed in, or attached to, a hot fluidside 1720 of a waste heat-carrying fluid pipe 1730. Additionally oralternatively, a helical channel 1740 can be formed or placed inside ahousing 1750 that surrounds at least a portion of the fluid pipe 1730.

Referring now to FIG. 57 an implementation of an apparatus is shown thatharvests thermal energy from a plane or curved surfaces. The thermalenergy harvesting apparatus includes a hot surface 1810 that is heatedby an external heat source via radiation or by an electrical source.Examples of external radiation heat sources include solar radiation,molten metals used in industrial processes, and surfaces of operationalequipment (e.g., server computers that warehoused in server farms toprovide cloud storage). Electrical sources may rely on the Joule effect,or inductive heating. The heating work space 1820 is a thin largesurface that provides a large contact area for heat transfer. The inletflow path uses inlet pipe 1850 and outlet pipe 1830, wherein the flowdirection is assured by a flow control valve 1850.

Additionally, FIG. 58 shows an implementation of an enhanced heattransfer apparatus shown in FIG. 57, but with a further heat transferfeature. This enhanced heat transfer apparatus further includes aplurality of pins 1910 made of a material having a high thermalconductivity. The plurality of pins 1910 are each coupled at one end tothe hot surface 1810 while the other end of each pin is immersed in thefluid working space 1820. Thus, heat is conducted from the hot surfaceto the fluid via the pins 1910.

Referring now to FIGS. 59A and 59B, in some implementations, thermalenergy is converted directly to hydraulic energy by using wax dilatationand phase change. A rotational work space body 2001 powered by anexternal rotational unit 2002, is driven using the shaft 2003. Therotational body 2001 contains radial workspaces 2007 and 2008 thatcontain the wax. Due to rotation of the body 2001, the workspaces areexposed to the thermal radiative or convective heat surface 2006. Thewax 2005 inside the workspace 2007 expands and converts into a liquidphase, thereby increasing its volume and pushing the hydraulic liquidinside the workspace 2007 through the hydraulic pipe 2010 attached tothe housing 2011 to the hydraulic power circuit. The returning fluidenters the workspace 2008 through the hydraulic pipe 2009 and cools downthe wax 2008. The workspace 2008 is in contact with the hydraulic tank2211 to cool the hydraulic liquid.

The following related applications to which this application claimspriority, are hereby incorporated herein by reference in theirentireties: (1) Continuous Convection Heat Exchanger, U.S. Ser. No.62/498,347, filed Dec. 21, 2016, (2) Hybrid Energy Recovery System forVehicle Applications, U.S. Ser. No. 62/498,348, filed Dec. 21, 2016, (3)Integrated Hybrid Energy Conversion and Storage System, U.S. Ser. No.62/606,511, filed Sep. 26, 2017, (4) Hydraulic Accumulator, U.S. Ser.No. 62/577,630, filed Oct. 26, 2017, and (5) Fluid Thermal Unit, U.S.Ser. No. 62/580,360 filed Nov. 1, 2017.

Additionally, U.S. provisional patent application nos. 62/496,784, filedOct. 28, 2016; 62/498,349, filed Dec. 21, 2016; 62/498,338, filed Dec.21, 2016; 62/498,337, filed Dec. 21, 2016; 62/498,336, filed Dec. 21,2016; 62/605,291, filed Aug. 7, 2017; 62/605,283, filed Aug. 7, 2017;62/606,522, filed Sep. 26, 2017; 62/606,521, filed Sep. 26, 2017;62/584,650, filed Nov. 10, 2017; 62/598,366, filed Dec. 13, 2017; and62/598,364, filed Dec. 13, 2017; as well as U.S. non-provisional patentapplication Ser. No. 15/731,383, filed Jun. 5, 2017; Ser. No.15/731,360, filed Jun. 1, 2017; Ser. No. 15/731,267, filed May 15, 2017;and Ser. No. 15/731,271, filed May 15, 2017; and PCT application no.PCT/US17/58883, filed Oct. 27, 2017, are hereby incorporated herein byreference in their entireties.

The various embodiments described above can be combined to providefurther embodiments. These and other changes can be made to theembodiments in light of the above-detailed description. In general, inthe following claims, the terms used should not be construed to limitthe claims to the specific embodiments disclosed in the specificationand the claims, but should be construed to include all possibleembodiments along with the full scope of equivalents to which suchclaims are entitled. Accordingly, the claims are not limited by thedisclosure.

1. An integrated hybrid energy recovery and storage system forrecovering and storing energy from multiple energy sources, the systemcomprising: an accumulator unit that includes a high pressureaccumulator and a low pressure accumulator, the accumulator unit havinga first side and a second side; at least one piston mounted forreciprocation in the high pressure accumulator, the accumulator unitconfigured to receive, store, and transfer energy from the hydraulicfluid to energy storage media; two or more rotational directionalcontrol valves, wherein at least one rotational directional controlvalve is positioned on each side of the accumulator unit, eachrotational directional control valve includes multiple ports; the highpressure accumulator is connected to a port of the rotationaldirectional control valve on the first side and a port of the rotationaldirectional control valve on the second side, the low pressureaccumulator is connected to a port of the rotational directional controlvalve on the first side and a port of the rotational directional controlvalve on the second side; and two or more variable displacementhydraulic rotational units, wherein at least one variable displacementhydraulic rotational unit is positioned adjacent each of the rotationaldirectional control valves, each variable displacement hydraulicrotational unit connected to a rotational directional control valve viaa port of the rotational directional control valve and a hydraulic pipe.2. The system of claim 1, further comprising a first mechanicaltransmission with a mechanical input coupling connected via a firstmechanical shaft to one of the variable displacement hydraulicrotational units of the two or more variable displacement hydraulicrotational units.
 3. The system of claim 1, further comprising a secondmechanical transmission with a mechanical output coupling connected viaa second mechanical shaft to another of the variable displacementhydraulic rotational units of the two or more variable displacementhydraulic rotational units.
 4. The system of claim 1, further comprisinga hydraulic connector that links the high pressure accumulator with ahydraulic circuit.
 5. The system of claim 4, further comprising ahydraulic connector that links the low pressure accumulator with thehydraulic circuit.
 6. The system of claim 1, further comprising apressure valve that enables hydraulic fluid to be released if peak loadsoccur to the low pressure accumulator, by way of a connection pipe. 7.The system of claim 1, further comprising a hydraulic pipe that is usedas a bypass connection to the high pressure accumulator.
 8. The systemof claim 1, wherein the energy storage media is an elastic component. 9.The system of claim 1, further comprising a controller that regulatestransfer of the recovered energy in the accumulator.
 10. The system ofclaim 9, wherein the controller directs pressurized hydraulic fluid to avariable displacement hydraulic rotational unit via a rotationaldirectional control valve.
 11. The system of claim 1, wherein thevariable displacement hydraulic rotational unit acts as a motor drivenby pressurized fluid.
 12. The system of claim 1, wherein the system isconfigured to recover, store, and release energy in a controlled mannerbased on availability and power requirements.
 13. The system of claim 1,wherein the energy source is radiative, electrical, vehicular, wind,wave, solar, or waste heat.
 14. The system of claim 1, wherein thevariable displacement hydraulic rotational unit is able to act as ahydraulic pump, and alternatively the variable displacement hydraulicrotational unit is able to act as motor.
 15. The system of claim 1,further comprising an energy recovery component that recovers energyfrom multiple energy sources.
 16. The system of claim 1, furthercomprising a thermal unit from which energy is recovered by the system.17. A hydraulic accumulator system, comprising: an outer housing; afirst open chamber within the outer housing; a second open chamberwithin the outer housing; an inner dividing wall that separates thefirst open chamber from the second open chamber; and a conduit thatextends through the inner dividing wall along a length of the hydraulicaccumulator system.
 18. The hydraulic accumulator system of claim 17,further comprising: a hydraulic flow control valve coupled to the firstopen chamber and to the second open chamber; and a hydraulic motorcoupled to the hydraulic flow control valve.
 19. The hydraulicaccumulator system of claim 18, further comprising: a wheel coupled tothe hydraulic motor.
 20. The hydraulic accumulator system of claim 19,further comprising: an axle extending through the conduit, the wheelcoupled to an end of the axle.
 21. The hydraulic accumulator system ofclaim 17, wherein the outer housing has a circular cross-sectionalshape.
 22. The hydraulic accumulator system of claim 17, wherein theouter housing has a elliptic cross-sectional shape.
 23. The hydraulicaccumulator system of claim 17, wherein the inner dividing wall iselastomeric and deformable, and wherein the inner dividing wall storesenergy by deforming when a first pressure within the first open chamberdiffers from a second pressure within the second open chamber.
 24. Thehydraulic accumulator system of claim 17, wherein the first open chamberincludes a high-pressure accumulator and the second open chamberincludes a low-pressure accumulator.
 25. The hydraulic accumulatorsystem of claim 17, further comprising: an elastic element positionedwithin the first open chamber.
 26. The hydraulic accumulator system ofclaim 25, further comprising: a first piston that seals the elasticelement within the first open chamber.
 27. The hydraulic accumulatorsystem of claim 26, further comprising: a second piston that seals theelastic element within the first open chamber.
 28. The hydraulicaccumulator system of claim 25, wherein the elastic element is amechanical helical spring.
 29. The hydraulic accumulator system of claim25, wherein the elastic element is a mechanical disc spring.
 30. Thehydraulic accumulator system of claim 25, wherein the elastic element isan elastomeric hose.
 31. The hydraulic accumulator system of claim 25,wherein the elastic element is a compressed gas.
 32. The hydraulicaccumulator system of claim 17, further comprising: two elastic elementspositioned within the first open chamber.
 33. The hydraulic accumulatorsystem of claim 32, wherein the two elastic elements have differentelasticities.
 34. The hydraulic accumulator system of claim 17, furthercomprising: three elastic elements positioned within the first openchamber.
 35. The hydraulic accumulator system of claim 17, furthercomprising: a first port allowing hydraulic access to the first openchamber; and a second port allowing hydraulic access to the second openchamber.
 36. The hydraulic accumulator system of claim 35, furthercomprising: a third port allowing hydraulic access to the first openchamber; and a fourth port allowing hydraulic access to the second openchamber.
 37. A heat exchanger, comprising: a combustion chamber havingan inlet port and an exhaust outlet port that define a combustion gasflow path between the inlet port and the exhaust outlet port; and afluid conduit oriented transverse to the combustion gas flow path, thefluid conduit directing the fluid through the combustion chamber, thefluid conduit including thermally conductive elements from which thefluid absorbs heat of combustion from within the combustion chamber. 38.The heat exchanger of claim 37, further comprising a second inlet port,the first and second inlet ports permitting two different fuel types toenter and mix within the combustion chamber.
 39. A heat exchanger,comprising: a combustion chamber having an inlet port and an exhaustoutlet port that define a combustion gas flow path between the inletport and the exhaust outlet port; and a fluid conduit coiled within thecombustion chamber, the fluid conduit arranged in a circular paththrough the combustion chamber, the fluid conduit including thermallyconductive elements from which a fluid within the fluid conduit absorbsheat of combustion from within the combustion chamber.
 40. A heatexchanger, comprising: a plurality of radiative burners having a commoninlet port, and a common exhaust outlet port, the radiative burnersconfigured to transfer heat of combustion by radiation; and a pluralityof fluid panels substantially aligned with one another andinterdigitated with the radiative burners, the fluid panels arranged todirect fluid in close proximity to the radiative burners so as to absorbthe heat of combustion.
 41. A hybrid heat exchanger, comprising: acylindrical combustion chamber having an inlet port and an exhaustoutlet port; a cylindrical fluid chamber coaxial with, and internal to,the cylindrical combustion chamber; and an electric heater having aresistive heating element that is coaxial with, and internal to, thecylindrical fluid chamber, the cylindrical fluid chamber thus arrangedto absorb either heat of combustion from the combustion chamber, or heatradiated by the electric resistive heater, or both radiated heat andheat of combustion at the same time.
 42. A heat exchanger, comprising:an elongated heat source; and a U-shaped fluid conduit that circulatesfluid proximate to the elongated heat source so as to absorb heat fromthe elongated heat source, the U-shaped fluid conduit being made of athermally conductive material.
 43. The heat exchanger of claim 42,wherein the elongated heat source is a hot surface.
 44. The heatexchanger of claim 42, wherein the elongated heat source is a waste heatcarrying fluid pipe.